[HN Gopher] I've acquired a new superpower
___________________________________________________________________
I've acquired a new superpower
Author : wirtzdan
Score : 864 points
Date : 2025-01-10 14:34 UTC (8 hours ago)
(HTM) web link (danielwirtz.com)
(TXT) w3m dump (danielwirtz.com)
| MarkusWandel wrote:
| Wait, that's not crossing your eyes, it's uncrossing them.
| Ordinarily if you look at something nearby, your eyes aim at a
| common spot. But when viewing a stereogram, you need to convince
| your eyes to aim at a spot more distant than the subject.
|
| This is easy with practice, however IMHO it helps to be
| significantly nearsighted. Then you simply take off your glasses,
| and can look at something nearby with infinity focus, which is
| naturally associated with uncrossed eyes.
|
| I don't know whether it's possible to train yourself to diverge
| your gaze, i.e. stereoscopically see images that are separated
| more than your pupil distance. Certainly I can't do that.
| semireg wrote:
| While intuitive, I'm not so sure. I look at the center line and
| slowly cross my eyes until the 3rd image slides into place and
| then I get focus lock. At no time do I feel my eyes uncross and
| go the other way. Hmm!
| satvikpendem wrote:
| See my other comment about cross view vs parallel view, looks
| like you can do one vs the other and the author can do the
| opposite.
| vault wrote:
| Wow. Thanks to MarkusWandel I discovered I can focus images
| while crossing my eyes and finally understood your comment.
| I've always done the "uncrossing" since I was a kid.
| teddyh wrote:
| Both work equally well if you just want to spot differences.
| Cross-eyed view is somewhat easier to do, since people
| naturally cross their eyes when looking at something close to
| their face, but there is no natural reason for one's eyes to
| diverge. But cross-eyed view also gives a subjectively smaller
| image, and is also not the usual way autostereograms are made
| to be seen.
| jodrellblank wrote:
| > but there is no natural reason for one's eyes to diverge.
|
| When you've finished looking at something close to your face
| and your eyes need to uncross. So you do that eye movement
| while still holding the image close to your face. Note you
| are looking "past" where the image is. As long as the image
| is closer than your infinity focal view you can do this, it
| doesn't have to be close to your face necessarily, Magic Eye
| posters on walls do work.
| phailhaus wrote:
| For spot-the-difference, crossing your eyes is more effective
| and easier to "dial in" than uncrossing them. You're
| essentially making each eye look at the opposite image. If you
| try uncrossing, then you need to make sure the images are at
| the exact correct distance to cause them to overlap with that
| technique, because you can only uncross your eyes enough to
| look straight ahead.
| nemetroid wrote:
| Looking uncrossed at the images in the article on my phone, I
| can easily achieve the effect uninterrupted between fully
| stretched arms and about half that.
| phailhaus wrote:
| Sure, but that's the limit. I didn't say it was impossible,
| just that crossing your eyes basically works all the way up
| to your nose.
| ses1984 wrote:
| It's a good thing that properly designed stereograms take
| this into account and don't require you to uncross your eyes
| past that point.
| phailhaus wrote:
| That's because _you_ have to find the distance between your
| eyes and the stereogram to make it work. Crossing your eyes
| is easier because your eyes can turn inwards far more than
| they can turn outwards, so it works at more distances.
| seeekr wrote:
| Is that true? It seems that our eyes are mechanically capable
| of looking in divergent directions, what's the reason that
| we're not able to "uncross" them beyond looking straight
| ahead? (Edit: Anecdotally I can confirm for myself that I'm
| not able to do it, so wondering if there's anyone that can.)
| thfuran wrote:
| From a control system standpoint, if you have one control
| that rotates both eyes the same number of degrees left or
| right to determine gaze direction and another to rotate
| both eyes the same (positive) number of degrees inward to
| control fixation distance, you can't specify the left eye
| rotated left of center and the right eye right, even if
| each eye physically can rotate that way. Not sure if that's
| how eyes actually work though.
| satvikpendem wrote:
| Note that there is a difference between crossview and parallel
| view. See this image [0] and try to overlap them. Depending on
| what you see in the foreground, that is the type of view you're
| able to see.
|
| Basically, it determines whether the 3D view you're seeing from
| the stereoscopic pair is convex (pops out of the page) or concave
| (goes into the page). It is of course possible to learn both
| views but most people naturally see one or the other. You can go
| to r/crossview or r/parallelview depending on which one you see.
|
| [0] https://i.redd.it/g5ilwgk99r781.jpg
| alt227 wrote:
| I find that there are different techniques to seeing both.
|
| If I stare at the image and cross my eyes until focus lock I
| get crossview where the image goes back into the page.
|
| If I bring the image right up to my eyes and stare through it
| into the distance, then slowly move the image backwards into my
| gaze until I get focus lock, then I get parallel view where the
| image pops out of the page.
|
| I have always wondered the difference between the two and why
| it happens. Thanks for shedding some light on it :)
|
| EDIT: I have just managed to achieve both without moving my
| head or the image for the first time in my life! Just by trying
| to look further 'past' the picture into the distance, and then
| by slightly crossing my eyes and focussing at a point in front
| of the picture.
|
| I have been trying to do this for 30 years, and it is only your
| explanation which helped me to do it. Thanks so much!
| jasonjmcghee wrote:
| I had never done the parallel view before either- spent 5 or
| so minutes at it and finally got it. For me it's still takes
| a fair amount of effort to maintain it (unlike cross view
| that takes effort to stop seeing it instead) but the 3d looks
| way more impressive somehow. Like the Toronto crowd one-
| hadn't seen so much depth in a "magic eye" before
| wruza wrote:
| I believe it's better because it is more natural to eyes.
| You may also want to play with the perspective. E.g. the
| hall here looks much better from 0.4m than up close on my
| phone due to the picture's perspective.
| https://triaxes.com/docs/3DTheory-
| en/522ParallelCrosseyedvie...
| Terretta wrote:
| Note that for parallel viewing the left edges (or centers) of
| the images should not be farther apart than your own eye
| spacing aka interpupillary distance (IPD) sometimes just called
| PD.
|
| That imgur may need to be shrunk depending on your screen for
| parallel to work.
| jeffhuys wrote:
| I can do both pretty comfortably, but there's a definite bias
| to parallel, way easier for me.
| a1o wrote:
| A new way of doing git diff, leave both versions of the code side
| by side and cross your eyes.
| louiechristie wrote:
| My thoughts exactly. Could be done with a git diff in a VR
| headset
| xattt wrote:
| If you're already spending the computing effort to create the
| VR image...
|
| /s
| justahuman74 wrote:
| I sure didn't expect there to be a plausibly work-related angle
| when I came to this thread
| bicx wrote:
| New business idea: git diff, but it uses Mechanical Turk to
| hire an army of cross-eyed diff spotters.
| waffletower wrote:
| There is a wonderful stable diffusion prompt here.
| satvikpendem wrote:
| Somewhat related, but I've been using the Semantic Diff
| extension in VSCode, works better than standard git diff.
| Damogran6 wrote:
| I was really good at the random dot stereograms. This is a really
| cool recasting of that skillset.
| alt227 wrote:
| I think thats the best part of this skill. Everyone did 'Magic
| Eye' images as a kid, but to be able to take that useless skill
| and apply it to something more useful and interesting is really
| cool.
| ChrisMarshallNY wrote:
| Dammit!
|
| I can't uncross, now!
|
| https://www.youtube.com/watch?v=qaz2hxZLycY
| Fauntleroy wrote:
| I'm not sure this works if you have astigmatism
| mikepurvis wrote:
| I did until it was corrected with LASIK a year ago, and I could
| still do magic eyes, both with and and without my glasses on.
| ehayes wrote:
| I have a small astigmatism (and wear glasses) and I was able to
| do it, but I feel like if I did any more today I'd have a
| headache.
| EvanAnderson wrote:
| Having similar acuity in both eyes made a huge difference for
| me. I'm somewhat astigmatic but was able to do this eye
| "uncrossing" trick just fine. I had a significant loss of
| acuity in one eye and that's what left me unable to do this (or
| to watch 3D movies).
| edelbitter wrote:
| de-clickbaited: to spot minor differences between two images,
| view them like stereograms
| erwincoumans wrote:
| That's fun, it worked for me as well. I could spot the difference
| in all images, including the 'impossible mode'.
| etaioinshrdlu wrote:
| Who's been doing this since they we're maybe 7 years old :)
| tobr wrote:
| Checking in!
|
| I'm frequently baffled by how unaware most people seem to be
| about the absolute basics of how their eyes work. Like, people
| don't even seem to be aware of how their stereo perception is
| largely made from two images, or any of the implications that
| has. I actively think about the two images maybe dozens of
| times per day.
| graypegg wrote:
| Chill out, that's a bit of hyperbole isn't it? This is just a
| trick for doing a spot the difference puzzle. It's not
| exactly a daily task most people are thinking about.
|
| Most people at least understand that stereographic vision has
| something to do with 3D perception because we've all closed 1
| eye before.
| tobr wrote:
| It's a useful way to compare visual things, which comes up
| in all kinds of contexts other than these puzzles.
| jeffbee wrote:
| I figured everyone because I had a puzzle book that instructed
| readers to do this.
| knallfrosch wrote:
| We've had these stereoscopic books with hidden images and I
| never saw any. So I've been failing at this since 7 years old
| - does that count?
| lowdest wrote:
| Yup I used to do this with tile floors as a child.
| ThrowawayTestr wrote:
| Neat. If this isn't working for you, try on mobile. It's easier
| if the images are small.
| dreadlordbone wrote:
| This helped, thanks.
| rufus_foreman wrote:
| You can also just back away from the screen. For the 3rd one I
| had to back up about 6 feet from my monitor before it clicked
| into place, once it is in focus you can move closer to see the
| difference better.
| dreadlordbone wrote:
| For some reason when attempting this my neck starts cramping
| etaioinshrdlu wrote:
| Who's been doing this since they were maybe 7 years old :)
| ktzar wrote:
| I used to use that trick with some arcade game that was popular
| in bars in 00s Spain. People were just impressed!
| FL410 wrote:
| Very cool. Even the impossible mode one was relatively easy!
| tunnuz wrote:
| That's so cool, thanks for sharing this. I managed to do all of
| them, in the impossible one I identified correctly the area, but
| couldn't pinpoint the difference.
| rstarast wrote:
| that's why they mirror one of the images in "find the
| differences" in puzzle competitions, e.g. USPC
| https://wpc.puzzles.com/uspc2024/
| doctoboggan wrote:
| I've been doing this since I was a kid as well. When I was
| younger some restaurants would have video monitors with games on
| them, and one of them was spot the difference. I essentially
| maxed out the score and still held the highest score when I came
| back in town years later. I wonder if its still around...
| voidUpdate wrote:
| I've heard about this before, but I've never actually managed to
| do it until just now. I needed to sort of "tune the parameters" a
| lot so that my eyes were crossed but also focused, since I've had
| a lot of trouble actually getting them in focus when I'm doing
| it, and the effect isn't as pronounced as I expected it to be
| idiotsecant wrote:
| I think you're still not doing it quite right. The effect is
| really quite obvious and pronounced.
| piva00 wrote:
| It took me some attempts but I agree, it's very obvious, the
| 2nd image made it glaringly obvious after I managed it well
| on the 1st one.
|
| My eyes get very watery after just a few seconds though,
| curious to hear from others how common this side-effect is.
| TonyTrapp wrote:
| Doesn't work for me. Just like stereograms. I just don't know how
| to "tell" my eyes to cross. Maybe similar to how I didn't figure
| out until I was 20-something how finger snipping works. Maybe by
| the time I'm 50 I can cross my eyes...!
| dgacmu wrote:
| To do it with crossed-eye view, try looking at your finger and
| slowly moving the finger closer to your eyes until you see a
| third image come into view in between the two on the screen. At
| some point your brain will/might let you focus on that image.
| alt227 wrote:
| You dont 'tell' your eyes to cross, you just look closer or
| further away. Try looking at the image at normal distance,
| whilst imaginging that you are looking into the distance at a
| beautiful view or at the horizon on an ocean. It is this
| difference in distance focusing which causes the illusion.
| s3krit wrote:
| Actually, given enough practice, you can literally just get
| your eyes to do it. I started doing magic eye puzzles as a
| kid and loved it, so just eventually learned how to control
| my eyes in that way. Even today, if I see any repeating
| pattern, or even anything vaguely similarly shaped, I can't
| help but do it
| jeffhuys wrote:
| When they snap together it feels soo good...
| Karawebnetwork wrote:
| Whenever I try to do this, the most I get is that the two
| images touch. The cats in the example are holding paws, but
| they never overlap. I've been trying to make this work since
| the old magic images from the 90s, but I've never managed it.
| I wonder if there isn a hardware limitation related to my eye
| configuration.
| JTyQZSnP3cQGa8B wrote:
| Well actually, I've been telling my eyes to cross since I was
| a child. I can't describe it, it's like tensing a muscle in
| the eyes or something and you can control the angle with the
| tension.
| jeffhuys wrote:
| I can even rotate my eyes! Did you know we have muscles for
| that? I trained it in the mirror - try tilting your head
| and look at your eyes REALLY closely: they rotate a bit to
| cancel out the tilt.
| dspillett wrote:
| The never work for me because my eyes don't work well together.
| Just not team players. I'm almost always looking through just
| one or the other, annoyingly usually the one that would least
| be preferable.
| SysComp wrote:
| Not working for me
| the__alchemist wrote:
| If you've done Magic Eyes, this is straightforward. Was able to
| get all 3 of the test images quickly.
|
| This is with focusing beyond the screen. Focusing in front of the
| screen is something I am unable to do, and not for want of
| effort.
|
| Also, your eyes might accidentally do this if looking at tiled
| patterns, e.g. wallpaper.
|
| Relative image size (e.g. view distance) is important.
| mikepurvis wrote:
| I have a slightly lazy right eye, so this has always come
| naturally to me, but I will say it's considerably easier to
| achieve the false focal lock on printed material-- something
| about screens, even quality ones with high refresh rates, just
| isn't the same.
| johnthedebs wrote:
| As a kid, I got a Magic Eye book and learned to see it by
| crossing my eyes (ie, focusing in front of the screen). I
| thought it was pretty interesting when I realized that I was
| seeing all the images inverted ("peaks" were "valleys" and vice
| versa) due to the way I was focusing. Alas, I never was able to
| see the images "correctly".
| ses1984 wrote:
| Instead of crossing your eyes to focus in front of the image,
| you have to uncross them and focus on something behind the
| image. Put your finger about six inches in front of your face
| and then look at the horizon. If the horizon is in focus you
| should see two fingers.
| whatshisface wrote:
| Focusing behind is much easier because you can get yourself
| started by focusing on an actual object.
| aidenn0 wrote:
| Focusing in front can be done by focusing on an actual
| object too? Many people e.g. put a finger between them
| and the picture and then remove it.
| whatshisface wrote:
| The finger method interferes more with the third image in
| my experience.
| andrewla wrote:
| Same -- much harder to get them to go the other way. I'm
| surprised that cross-eyed random dot stereograms never took
| off; so much easier to do.
| kayge wrote:
| It's funny because even if you do the Magic Eye pictures
| "correctly" (focusing past them) you can still get funky
| images by going too far and locking the surrounding pattern a
| second time. If I remember right the first time I did this
| was on a heart picture (similar to [0]), which ends up
| looking like a big puffy W stacked on top of a slightly
| larger puffy W :D
|
| [0] https://i0.wp.com/www.magiceye.com/wp-
| content/uploads/2018/1...
| teleforce wrote:
| Thanks that's one of the beautifully crafted magic eye
| images, bring me back memories about 20 years ago when it
| was a craze.
| SamBam wrote:
| Are you sure that's supposed to be a heart? I see the three
| peaks of a "W" as well -- I think it's supposed to be a
| tulip, no? That also matches the background theme.
| dotancohen wrote:
| The background is flowers, but the hidden image is most
| certainly the classic heart shape.
| BenjiWiebe wrote:
| If you see 3 peaks you went too far - which is really
| easy to do on mobile. I had to be careful to go only
| "once deep".
| kayge wrote:
| Yep, well at least 98% sure anyway. But you're right,
| that 'second level' image does look a lot like a tulip,
| much better description than what I said about W's :) And
| of course this led me to try zooming out a bit and going
| for level 3+... kinda feels like I'm looking down at the
| top of a strangely shaped wedding cake, which would also
| go nicely with the flowers and heart theme. Thanks for
| giving me an excuse to take another look!
| lynguist wrote:
| I think I just locked the pattern also a third time where
| it looks like pillars but I'm not sure if I saw it
| correctly.
|
| When I first looked at this picture I saw the W pattern and
| then blinked and suddenly saw the intended pattern.
|
| When you lock on the non-intended ones it feels somehow
| like a secret/forbidden path you shouldn't go, like
| consuming drugs.
| SoftTalker wrote:
| I can get the images to merge but the differences don't stand
| out.
| the__alchemist wrote:
| Are you able to confirm the images are completely aligned?
| You can do this using landmarks, like the brightest stars on
| the telescope pic. I.e. if you see more than one of any
| landmark, it is not aligned. You may need to adjust zoom, and
| distance from face.
| mNovak wrote:
| I find there's a two step process, first overlapping the
| images (but which makes the images blurry), then letting my
| eyes refocus so the middle image is crisp. Only then does 3D
| or shimmer effect happen. Takes some practice to merge the
| images while maintaining focus for me.
| layer8 wrote:
| I've done Magic Eyes a lot, but I'm failing on this. (However,
| I found the difference in the coffee beans picture reasonably
| fast without the eye-crossing trick, and before reading what
| the difference is.)
| adeon wrote:
| Maybe we are the opposite. As a kid, I could only do cross-
| eyed-focus-in-front-of-screen, but not "focus beyond the
| screen". Or a book at the time.
|
| So I was able to see the 3D in Magic Eyes, but the 3D effect
| was inverted.
|
| Today as an adult I am able to focus beyond the screen, but
| it's still much easier for me to do it cross-eyed.
|
| I also got all the images in the post almost right away. But my
| eyeballs focused in front instead > _ <
| naet wrote:
| I'm great at magic eyes / stereograms and have a ton of posters
| around my house with them, but I still had trouble with seeing
| the differences in the test images. I easily locked in my focus
| on the overlapping cat images but only one difference stood out
| to me. I eventually got them all but it wasn't that easy (maybe
| with practice I could get there). The differences are
| noticeable when I focus right on it, but when I'm looking at
| the whole image it's harder to tell what is missing from one
| eye.
| manbash wrote:
| Are you able to look around while keeping your "unified
| vision"?
|
| To me, all the differences appeared to be flashing (probably
| my brain alternates between the pair of images it attempts to
| "lock in", or something to that effect).
| crazygringo wrote:
| Yup, I loved Magic Eyes as a kid. This was easy.
|
| Nevertheless, I was astonished that "impossible mode" literally
| took me only 1-2 seconds to find the missing star.
|
| Like, I knew our vision is good at interpreting depth from
| images. I figured it would be all right at finding large areas
| of differences. I had no idea a single freaking pixel could
| stand out like a sore thumb.
| sailfast wrote:
| I had trouble finding the "shiny" pixels on that one simply
| because the stars also had that issue - but after enlarging
| the image a bit more and scanning back and forth I was able
| to pick things out a bit better.
|
| Now, ask me to look at my code again for a couple minutes and
| it might be tough but it worked :)
| whywhywhywhy wrote:
| This same technique can be used for a 3D effect:
| https://old.reddit.com/r/CrossView/
| not_a_bot_4sho wrote:
| Every Asshole knows this trick for targeting spacecraft
|
| https://youtu.be/XGdjKvivJA8?si=lRrfl6rHzAsE7nEO
| robofanatic wrote:
| Thanks! now I have a migraine
| chrisbrandow wrote:
| Every 80's kid knows this trick from those old books where you
| cross your eyes to reveal images.
| tobr wrote:
| More things you can use this for:
|
| "Are these two things the same size?"
|
| "Are these things that are supposed to be evenly spaced actually
| evenly spaced?"
|
| "Are all these things straight/at the same angle?"
|
| "Is the wallpaper pattern aligned everywhere?"
|
| "Is that surface using a repeating texture?"
| OscarCunningham wrote:
| This is called 'vdiff' in the Jargon File:
| https://jargonfile.johnswitzerland.com/vdiff.html
| Jzush wrote:
| I didn't know this had a name or was considered a skill. I've
| done this since the 90's when those magic eye books became
| popular.
|
| I even managed "impossible mode" in 2 or 3 seconds.
| Workaccount2 wrote:
| At a local bar they had a game machine, and if you got a high
| score on any of the games, your tab for the evening was free.
|
| One of the games was a "spot the differences" between two
| pictures with an ever decreasing timer for each round. Using this
| trick I was able to easily surpass the high score, and garner a
| crowd watching me perform this mind numbing feat.
|
| Probably my peak fame right there.
| soco wrote:
| I can't overlap the images to save my life - they get like
| halfway there and that's it...
| ThrowawayTestr wrote:
| Try on mobile, it's easier if the images are smaller.
| pivo wrote:
| Wow, yeah it happened immediately for me on mobile while I
| couldn't get past half way on my monitor. Thanks!
| physicles wrote:
| Are you crossing your eyes (focusing nearer than the object)
| or diverging them (focusing past it)? Diverging is a harder
| skill to learn.
| soco wrote:
| Not even sure which one I should try :) but yes tried both
| to no avail. Maybe it's just not something to achieve in
| the first try...
| wruza wrote:
| For crossing just focus on your finger and then remove
| it.
|
| Looking far away may be harder, and afaik it's near
| impossible to look "past infinity", iow pictures must be
| less wide than the distance between your eyes.
|
| Btw these two methods aren't equivalent in watching
| stereograms. If you look at one and see _something_ but
| it doesn't really make sense, then it's probably the
| opposite chirality.
|
| Personally I hate the crossing method because it makes
| your eyes feel strange for a while.
| unkulunkulu wrote:
| how I approached crossing: first practice just crossing
| your eyes and observing how every object has two images
| in this case and when you slowly "uncross", they merge
| back into one. you can use anything in your surroundings.
|
| then for the stereogram you do the same, observe the out
| of focus edges of the left and right pictures, then
| slowly uncross until left and right image occupy the same
| spot as though they were the same object. now its out of
| focus, but one (ok, actually three, because there were
| two, you "doubled" that by crossing, then merged two of
| them. but ignore the other two and focus on the merged
| pair)
|
| sometimes you will merge images of the same picture, in
| this case you are just back at your normal vision, repeat
| :)
|
| then you try to keep them overlapped and focus the
| vision, try to "believe" that you are really looking at a
| single object.
| titzer wrote:
| Diverging is definitely harder, and might be out of focus.
| To keep in focus I found it easier to focus on the right
| image and then cross my eyes, rather than staring in the
| center and then staring through the screen into the
| distance while trying to make them line up.
|
| I used to not be able to do the "magic eye" 3d images until
| recently, and this trick is pretty handy.
| biomcgary wrote:
| Is diverging harder? I find it easier. Maybe it is from
| long ago practice on stereograms, but I'm curious if it
| could be due to neurological/physiological differences.
| grumbel wrote:
| Crossing is easier because you can simply hold your
| finger in front of your eyes and look at that for
| practice.
|
| Diverging requires you to look past the image, meaning
| you have nothing to really look at, which makes it
| difficult to figure out what your eyes are even supposed
| to do.
|
| Those stereograms aren't helping much either, since they
| look like nothing until you get it right. With cross-eye
| you have instant double-vision that you just need to
| align.
|
| Cross-eye also works across much larger distances,
| diverging fails when the images are too far apart.
| leni536 wrote:
| It depends on the image. If the two images are too far
| apart then it could require your eyes to diverge, and not
| to just converge slightly less. That might be impossible.
| BenjiWiebe wrote:
| Diverging is way way easier for me, but I am positive
| that's because of the 10's of hours (at least) that I
| spent staring at magic eye images as a child.
| paulsmith wrote:
| My whole life I've been doing stereograms by diverging, but
| I couldn't get the three images in the post (the pairs
| would get closer but never fully overlap), so I tried
| crossing based on your comment. It was way easier than
| diverging (obviously, since I couldn't do it otherwise),
| but it took me a few tries, because I think it's actually
| /too/ easy to cross your eyes compared to diverging - I was
| way overshooting when I crossed my eyes. The trick was to
| notice this, and then control the un-crossing until they
| lined up.
| waffletower wrote:
| That happened to me too but I persisted and eventually
| succeeded. I think I needed to cross my eyes slightly more
| than I was initially. I have been diagnosed with a minor eye
| convergence issue which makes it difficult to focus on near
| field objects in motion -- gaining this superpower was
| difficult but I did it without a headache thankfully.
| PaulHoule wrote:
| It's like
|
| https://triaxes.com/docs/3DTheory-
| en/522ParallelCrosseyedvie...
|
| which some people struggle with, somebody posted a
|
| https://en.wikipedia.org/wiki/Autostereogram
|
| to HN yesterday which some people get and others don't.
| (That's different from the "cross-eyed stereogram" because
| one of them involves having two images and the other one has
| one image with two images hidden in it)
| mhitza wrote:
| I can understand why it's hard for some. I've landed on
| that wiki page a while ago and couldn't figure it out. Then
| found a similar thing on an itch.io page that was easier
| for me to figure out.
|
| In these later examples (starting with the easy puzzle of
| the OP, and your 3d examples), I find that I do the process
| in two stages.
|
| Unfocus my sight until the third image shows up in the
| middle at the correct size (as a blurry mess). Then try to
| focus the center image.
| PaulHoule wrote:
| What's more a lot of people (maybe 20%) don't benefit
| from things like
|
| https://www.reald.com/
|
| which is one reason why stereo movies have struggled.
| (That plus some people get sick... Having both a flat and
| 3-d movie in two different theaters comes across as money
| grubbing to the consumer but it is really a money sink to
| the theater.)
| nis251413 wrote:
| Yeah that's me. I lack stereoscopic vision so such tricks
| or 3d glasses etc do not work.
| tartoran wrote:
| I have a big problem crossing my eyes too while having no
| problem with the parallel view way seeing stereograms. I am
| actually going to stop trying as my eyes started to hurt.
| DrSiemer wrote:
| Which one makes things become bigger? I learned that one
| first and then later figured out the one that makes the
| mixed image smaller (cross eyed I think?). Now I cannot
| do the big one anymore.
| NoMoreNicksLeft wrote:
| For me, what's difficult is holding my right eye closed
| without my left eye drifting to look at my nose. My right
| eye's good, I can move it and focus on anything within my
| (now peripheral-limited) view... but the left is wonky. I
| think I learned how to wink (and hold it) with the right
| really early, by age 3 or 4, but the other side I never
| tried until I was pre-teen... some sort of muscle
| atrophy?
|
| You can also tell if your head's level, just by crossing
| your eyes. If the two images are diagonal to each other,
| then your eyes/head aren't level. I have no idea what the
| possible use for that would be.
| rwmj wrote:
| I spent far too much time as a twenty-something generating
| autostereograms, which seems to have trained my eyes. I was
| able to "cross" the images on this page very quickly.
| KPGv2 wrote:
| NB autostereograms require you to move your eyes away from
| each other, the opposite of crossing them. To put it
| another way, crossing your eyes is what your eyes do when
| you're looking at something close to you, while the
| opposite is when you're looking far away.
|
| Which is why for ASGs people advise you to look _past_ the
| picture. Or why you bring the pic close to your eyes (so
| close that you basically have no choice but to look
| _beyond_ the picture)
| iforgotpassword wrote:
| You can easily generate inverted ones that require
| crossing your eyes to appear properly, but they don't
| look as nice since they pop out instead of going into the
| screen/book.
| BenjiWiebe wrote:
| Ever since I was a child addicted to the "magic eye"
| stereogram books, I've always diverged (not crossed) my
| eyes for spot-the-difference puzzles.
|
| Also, if you're doing it on a piece of paper, hold a pen
| in each hand spaced right so you see the middle (3rd)
| hand in the middle combined image, and move both hands in
| sync to circle all the differences. Kind of a cool way to
| point them out to someone else.
|
| The difficult puzzle took me about 10 seconds here since
| I was looking for more than one difference. I saw the
| first difference in about 1 second.
| antihero wrote:
| Is that the crossy-eye porn?
| jeffhuys wrote:
| Don't CROSS them. Relax them, like you're tired and can't
| focus on a computer screen.
| jeffhuys wrote:
| Also keep the size low. If you're having a hard time at
| 20cm from a 4k 30" monitor, it won't come easy. Zoom out.
| hk__2 wrote:
| There are two methods, either you cross them either you do
| like you're describing.
| arka2147483647 wrote:
| You can actually do it both ways, but which is easiest for
| whom is different.
| jjk7 wrote:
| It helps me to see the depth and then properly focus to
| cross them very slightly to start, then as I see the image
| my eyes adjust to pull it in focus properly.
| Taek wrote:
| You might be too close to the screen.
| Tempat wrote:
| If you mean literally you can only bring them half way
| together, try just moving twice as far away.
| adamc wrote:
| Yeah, me either. My eyes really resist it. And after trying
| it a few times it messes up my focus for a bit.
| nadis wrote:
| Same! I feel like I can get a fleeting moment and then it's
| gone. I swear I could cross my eyes when I was a kid - I
| wonder if with practice it'll come back or if I'm just old
| and this skill I didn't-know-I-wanted is lost
| smusamashah wrote:
| There is a way to help yourself.
|
| Put the pair of images in front of your eyes.
|
| Bring your finger between your face and the image.
|
| Now look at your finger.
|
| Move your finger back and forth.
|
| While doing this, notice that at a particular distance, the
| images in background will perfectly overlap each other.
|
| That's your moment.
|
| Pull out your finger and look at that image.
|
| ---
|
| Should take lot less tries to learn doing it without finger.
| I have taught cross eye to my siblings and cousins using this
| method. But if you always need finger to focus it's fine.
| thayne wrote:
| I tried, this, and I can get it to overlap in the
| background, but as soon as I take my finger away, I lose
| it.
| OJFord wrote:
| You may have a very slightly 'lazy eye' (I do) - it can
| be a lot less extreme (not at all noticeable to others)
| than the pointing-completely-different-directions that
| people imagine, and iirc is highly correlated with
| astigmatism.
|
| Optician used to tell me to work the muscle by following
| my finger to my nose, trying to maintain a single image.
| At a certain point it will snap into two - the 'lazy' eye
| has given up and drifted slightly - the goal is to get
| the finger as close as possible. Obviously if you get
| very close or all the way, that's 'cross-eyed', but I
| just can't do it.
| AzzieElbab wrote:
| When I was six, some older kid showed me this trick, but I
| could never really cross my eyes. These days, I wear
| glasses, so I guess no new superpowers for me.
| scrozier wrote:
| The finger trick did it for me. As mentioned elsewhere, I
| used to do this academically (looking at protein
| structures), but I couldn't easily get back in the groove
| here without the finger.
| lr4444lr wrote:
| Treat it like a "Magic Eye" photo and just relax your eyes to
| a further focus point.
| hgomersall wrote:
| When it works you get what seems like 3 images with the
| middle one showing the differences; you can then relax and
| peruse the middle image at will. I guess all the practice
| with SIRDS as a child probably helps.
| loco5niner wrote:
| Here's another trick: open the image in a browser, then zoom
| out. The smaller the image (up to a point and you can find a
| sweet spot) the easier it is to get them to overlap. Once
| you've got it, slowly zoom in a bit at a time, re-acquiring
| the overlap at each stage.
| prashnts wrote:
| What really helped me was doing some sessions with an
| Orthoptist to reeducate my eyes. I used to see double when
| stressed sometimes and could never imagine to converge/cross
| my eyes and retain focus. With the reeducation I was able to
| see the Impossible one in focus after a couple tries.
| OzFreedom wrote:
| Same as in autostereogram, the trick is to look to the
| distance. Close your eyes and imagine a mountain far away or
| some distant object, notice how your eyes adjust to see it.
| Open your eyes and try to look at this imaginary mountain
| while the image is in front of you. When you see the third
| Image, treat it as if its a distant 3d object somewhere on
| the horizon.
| Ericson2314 wrote:
| That was me at first.
|
| I think the "cross eyed" phrase is a bit ambiguous.
|
| What I ended up with (I think) is a focal point not closer
| than the screen but farther than it. My eyes didn't want to
| do it at first but then they did.
|
| What is weird about it is the focusing and focal point are
| out of sync --- my brain can do it but the weird feeling is
| one of "gosh, this thing is a lot closer than it should be"
| where "should be" is based on focal point, and "is a lot
| closer" is based on focus.
|
| Don't want to do this too much, feels like I could easily
| decalibrate my brain for real life lol.
| duxup wrote:
| >Probably my peak fame right there.
|
| My son and I always make jokes about everyone's 5 minutes of
| fame. Some random person on the jumbotron at a sporting event
| "Yup, there's his moment, it's over now."
|
| At least yours got you something ;)
| klondike_klive wrote:
| One of my dad's sayings when somebody in a film delivered a
| line and then disappeared was "6 months rehearsal for that."
| jvm___ wrote:
| I envision happy families watching the end credits for
| Dad's name as Third Assistant Caterer on a big budget film.
| scrozier wrote:
| You may or may not be aware that Andy Warhol famously quipped
| that, "in the future, everyone will be famous for 15
| minutes," back in the late 1960s. As media has gotten to be
| ever more ubiquitous and the cost of entry lower, he was
| clearly onto something decades before the internet!
| sslalready wrote:
| And then there's Banksy's "in the future, everyone will be
| anonymous for 15 minutes". For pretty much the same reasons
| you stated above, I assume.
| pzs wrote:
| To update this excellent quote to 2025, change minutes to
| seconds and you just described TikTok.
| warner25 wrote:
| Yeah, I was thinking that the while modern social media
| has made the "cost of entry lower," and everyone can
| theoretically reach more people than ever, it's hard to
| even describe most of it as "fame" anymore. I mean, does
| content even "go viral" anymore, with users subdivided
| into the tiniest niche communities or audiences? Even if
| things get traction for a while, there's so much
| competition with so much other content that everything
| seems to get quickly drowned out and then can't even be
| found again later through search.
| warner25 wrote:
| Totally indulging in this side discussion: I remember
| thinking in high school and college that fame was the end-all
| of life, telling people that my goal was to have my own
| Wikipedia page. I saw it as something like the combination of
| being a "cool kid" (but for, you know, the whole of society
| instead of just one's school) and a sort of immortality.
|
| Anyway, over the last couple of decades as an adult, besides
| realizing the obvious - how terribly shallow that is, and
| missing so much of what's really good in life - I've realized
| how fleeting fame seems to be _even for the truly famous._
| Even looking over the list of US Presidents (never mind
| lesser political figures like VPs, cabinet members,
| congressmen, etc.) as someone who has always been interested
| in history, I look at some names and think, "who?" or "I've
| heard the name, but know nothing about him." I mean, of
| course you can still read about them, but that even a US
| President can be largely forgotten as a household name within
| 250 years is really a stunning thing to think about; they are
| ultimately no more immortal than someone who only has their
| name in a genealogy database or on a grave marker.
| throwaway743 wrote:
| Just got a funny visual of someone going crosseyed and focused
| on overcoming a challenge in front of them, with a crowd of
| people cheering them on.
| lxe wrote:
| I was about to post this same exact post :)
|
| Was the high score holder on there for a few years.
| sschwa12 wrote:
| This is my peak fame as well. I had the high score on every one
| of these I've played using this method. My friends were always
| try to figure out how we could make money doing it...
|
| The game is usually called 'Photo Hunt'
| bluedino wrote:
| Those Megatouch systems run Linux! Lots of fun messages to
| read on the credits screen or when you reboot them.
| hoistbypetard wrote:
| I haven't seen one in several years, but they always used
| to run Red Hat, based on the boot screens.
| lenkite wrote:
| Failed to perform the technique despite multiple retries, but
| didn't have any issues spotting differences the normal way for
| all except the impossible mode - which just felt like it would
| be tedious.
|
| My usual method is just to brute-force linear scan from left to
| right, top-to-bottom. May not be elegant, but it works.
| redcobra762 wrote:
| ...except as you say, it didn't work. The "eye-cross" trick
| gave the answer on the impossible one in ~10 seconds.
| NoMoreNicksLeft wrote:
| The impossible one was sub-2-seconds for me. I had to do it
| over to make sure it wasn't more than one difference...
|
| Makes you wonder if the kid he was talking about had a lazy
| eye or crossed eyes or something.
| hgomersall wrote:
| The impossible one was quite tricky, but I did find I was
| able to relax into the image and take my time. Probably
| took about 10 seconds.
| ElijahLynn wrote:
| Took me about 10m total to get it all the way to impossible
| mode. I think you can do it!
| K0balt wrote:
| Fun fact- when I was a teenager, my friends and I set up a
| stand in a local mall selling those "magic eye"posters. We
| made bank for a few months. But, there are actually a lot of
| people that medically cannot use the technique, or at least
| for whom it is extremely difficult or less vivid. Severe
| astigmatism, (obviously) blindness in one or more eyes, and
| certain attention deficits or fidgety types often have a
| difficult time.
|
| I, on the other hand, 37 years later,am basically permanently
| crosseyed from the experience lol. It somehow became a
| resting state for me from all of the practice, so I'm always
| doing it on any kind of repetitive patterns, and even
| "successfully" on random ones which does some really weird
| stuff in your visual cortex.
| codazoda wrote:
| Weird timing. I dunno why this works but I've been using it to
| see mice.
|
| You see, I noticed that I have a mouse problem in my garage. I
| figure if I've seen one mouse, there are probably more. So, I
| stood on some stairs in my garage and crossed my eyes to sort of
| blur the scene. It allowed me to catch movement more quickly and
| I was quickly watching multiple mice run around the edges of the
| area.
| idiotsecant wrote:
| That seems like not the same thing though, right? You're not
| doing a diff on two images, you're just losing resolution so
| you can direct more attention to movement.
| thunderbong wrote:
| I think it's because our peripheral vision is able to observe
| movements faster.
| mncharity wrote:
| Hmm. I noticed in lectures, if I stilled my eyes, most of the
| field of view would grey out, except for areas of motion (eg a
| lecturer's head or writing arm) which appeared normal. After
| motion stopped in an area, it would slowly grey out. When a
| motion started, its area would snap to normal, making it easy
| to spot onsets of motion. Eventually my eyes would twitch, and
| the whole field would refresh.
| iamjackg wrote:
| I've done this in the past with bugs in the grass. If I stare
| at a fixed point, I start seeing each individual bug moving
| through the grass, whereas normally they would be really hard
| to spot among all the fine details of the ground and grass
| blades.
| athom wrote:
| I first read about this back in the 1980s, in an issue of
| Science Digest. Couldn't find a link or reference on short
| notice, but here's something from the American Academy of
| Ophthalmology that explains the phenomenon, with an
| experiment to see the blood vessels in your eye:
|
| https://www.aao.org/eye-health/tips-prevention/experiment-
| se...
|
| Apparently, the brain tends to ignore visual stimuli that
| don't change over a short period of time, which allows you
| see "around" the blood vessels passing through the middle of
| your eye. By closing your eye, and moving a penlight around
| against your eyelid, you can make the vessels cast a shifting
| shadow on your retina that makes them visible.
|
| The reason you usually see everything out in front of you is
| that various actions cause your eye to shift about just a
| little, just enough to cause the image on your retina to
| shift about enough for the brain to notice.
| yegle wrote:
| I feel old knowing https://en.wikipedia.org/wiki/Magic_Eye
| egypturnash wrote:
| You can also now free-view stereo image pairs. Congratulations.
| robotguy wrote:
| When auto stereograms were all the rage in the late 80's I had a
| program on my Mac Plus that let me make/edit them and I used to
| edit for hours WHILE looking at them in 3D. Then one time I was
| walking down a hallway with a repetitive wallpaper pattern, my
| eyes did the thing, the entire hallway appeared to shift in front
| of me, and I stumbled and fell. Still to this day my eyes will
| sometimes automatically snap into 'alternate' focus when viewing
| a repetitive pattern.
| shaftway wrote:
| This happens to me too. Particularly when it's on a narrow
| horizontal repetition (like wooden slats on a wall).
|
| I attribute mine to playing a lot of the game Magic Carpet from
| the mid to late 90's. It had some interesting graphics modes,
| including Red/Blue anaglyph 3D and a stereogram 3D mode. It was
| fun to try to play it, but it used noise for the pattern, so
| you didn't get textures, only blobby shapes.
| wruza wrote:
| This happens to me easily inside cars with these dotted-
| breathing roof interior patterns. (Edit: g "perforated vinyl
| fabric")
|
| Well, worse than easily - sometimes I cannot get back to normal
| and am not sure how far it actually is, because the nature of
| the pattern allows to re-lock at every few cm. I just don't
| know where I'm really looking at unless there's an irregular
| object nearby.
| xamuel wrote:
| No need for the Mac Plus program, you can make these in any
| text editor. Use a fixed-width font and fill a line with a
| repeating word eg
|
| WORDWORDWORDWORDWORDWORDWORDWORDWORDWORDWORDWORDWORD
|
| Then copy that and paste it a bunch of times to make it multi-
| line.
|
| Cross your eyes so that the WORD's overlap (all except the
| leftmost and rightmost). You now see two cursors instead of
| one. Position your two cursors anywhere you want and then
| insert a space in order to make the corresponding WORD (or ORDW
| or RDWO or ORDW) sink into the screen. (Or rise if you
| parallel-view.)
|
| We used to do this in the computer labs back in 6th grade.
| nayuki wrote:
| I discovered this trick independently about a decade ago, to use
| cross-eyed viewing to easily spot differences between two similar
| images. Like you said, the parts that mismatch appear to shimmer
| and be unstable, making them obvious.
|
| However, I feel eye strain from doing it, so I prefer other
| methods. 99% of the time, I do
| https://en.wikipedia.org/wiki/Blink_comparator instead, just
| switching between two images with zero flicker and zero
| displacement offset. Also with both eyes, it's easier to spot
| certain kinds of subtle differences like color shifts, JPEG-like
| compression artifacts, tiny differences in antialiased
| renderings, etc.
|
| One benefit of the cross-eyed method, though, is that you can
| difference videos. But the use case for that is rarer than
| differencing images.
| jeffhuys wrote:
| To reduce eye strain, don't cross your eyes, but relax them
| (so, the other way). Instantly clear and snaps together as if
| magnetic.
| tartoran wrote:
| The problem I have with this is that instead of the images
| completely overlapping they overlap a section in the middle.
| I can't get both images to completely overlap and am getting
| some eye strain from trying to force them.
| claiir wrote:
| This is called "divergence" [1] and is less straining on your
| eyes than crossing them ("convergence" [2]) while being
| equally as effective spotting differences, even on video.
| It's also what your eyes naturally do when you watch
| stereoscopic 3D with tinted glasses--the stereoscopic images
| are pulled _out_ (divergence) not pushed _in_ (convergence
| /cross-eyed). I've been doing this since I childhood. If you
| get good at it, you can watch side-by-side 3D videos in 3D
| with just your naked eye (e.g. VR). I believe there's a
| reddit covering the more prurient variety of that!
|
| [1] https://en.wikipedia.org/wiki/Vergence#Divergence
|
| [2] https://en.wikipedia.org/wiki/Vergence#Convergence
| stavros wrote:
| The only problem with divergence is that you can't go too
| much farther out than the distance between your eyes,
| whereas convergence works for larger images as well.
| prmph wrote:
| A simple trick to doing this, in case it's not clear how to
| do it, is to try focusing on an imaginary point behind the
| screen as you look at the images. You will see a third image
| between the two start to come into focus. Now relax your eyes
| and look at that image. Simple, and quite a bit more relaxing
| than crossing your eyes.
|
| The only disadvantage to this method is that it seems there
| is a limit to how wide the middle image can be, i.e., the
| original images may not completely overlap.
|
| If you do want to cross your eyes but do not know how to do
| it, do the opposite of the above: try to focus on an
| imaginary point closer to you than the screen as you look at
| the images. This method is far more taxing on the eyes
| though.
| NortySpock wrote:
| I'll second the blink comparator method as a simple diff
| checker, or when comparing two chunks of code that are
| structured exactly the same way but somehow behave differently.
| (e.g. "what's the difference between these two functions" or
| "how is this yaml block different from that yaml block"?)
|
| Line them up as two tabs in the editor, flip very rapidly
| between the two repeatedly, and usually the difference is
| apparent in 5-6 flips.
| anarticle wrote:
| Incredible! This technique is also used for the 3d visualization
| of protein structures, it was called "cross viewing":
| https://imgur.com/cross-views-are-commonly-used-to-view-prot...
|
| You cross your eyes to get the two images to line up, hold it
| there and then try to adjust the focus of your eyes. It's a neat
| skill to have.
| meatmanek wrote:
| I found the toolbars and stuff around the edge of the image
| made it difficult for me to lock onto the crossview image in
| your example; surrounding it with more blank background makes
| it easier for me: https://imgur.com/a/NizzRgo
| dogman1050 wrote:
| The stars puzzle helped me find a speck of dirt on my phone
| screen.
| dylan604 wrote:
| The funny thing about the stars image is this is a common way
| to find asteroids, comets. It's not limited to just those. Only
| instead of a bunch of cross eyed astronomers, they overlay and
| align the images and do subtraction/difference filtering to see
| what's left. For comets/asteroids, the dot of interest will
| move between frames. Even just playing back the aligned images
| as a timelapse can reveal motion.
| norswap wrote:
| Wow that's interesting -- trying to cross my eyes produces
| hellish jitter.
|
| I suspect it's because my left eye is slighty lazy.
|
| But I was able to superimpose the right cat picture onto the left
| one (it's a lot harder for the more complex sky resort picture).
| It's pretty eerie, the right picture just slides right up the
| left one (I did need to figure out the right distance for it).
|
| It doesn't help me pick out the differences though, I mostly only
| see the right picture, and if try to focus my left eye, the right
| picture slides out. Still, intersting.
| xkcd-sucks wrote:
| Autostereogramming it doesn't help me lol
|
| If it's perfect, the overlapping regions just merge in color,
| i.e. the cat's paw becomes off-white. If it's not perfect, I
| still have to attend to which parts are popping in and out. In
| both cases I still have to compare the merged view to the left
| and right hand sides.
|
| Although it is very nice for illustrating each eye's
| contributions to the merged view. Just not an attention-saver.
| evan_ wrote:
| I use this technique to get web layouts pixel-perfect with the
| mockup, just put both windows next to one another and superimpose
| them with your eyes. Works great. There are tools that do this by
| overlaying an image with 50% alpha but it doesn't work as well.
|
| Last year when there was a bunch of fuss about Kate Middleton not
| having made any public appearances there was a minor flap where
| people claimed that a photo she'd released was just an edit of an
| earlier photo.
|
| There was a tweet presenting two photos, one old and one
| purporting to be new, where she was holding strikingly similar
| poses. The claim was that the new one was just an edit of the
| older one. I used this technique and immediately the minor
| differences stuck out like a sore thumb- her hand was rotated
| more in one, her hair was laid differently, etc.
| klik99 wrote:
| I picked this up during the magic eye craze of the 90s, and I
| will never not find it hilarious how people get shocked at my
| ability to find the differences. I always share the skill too,
| it's one of those things people find impossible until they get it
| and it's easy.
| twolf910616 wrote:
| dang it i just did this on a zoom meeting. hopefully no one saw
| me trying to cross my eyes
| TheRealPomax wrote:
| This is how I help my family when they're stuck on "spot the
| difference" steam games. It also takes literally any fun out of
| them, the actual game has to come from not (just) spotting
| differences, because that task is trivial.
| comonoid wrote:
| I knew some people who used it to compare aerial photos (though
| generally a special device with mirrors was used).
| hk__2 wrote:
| > though generally a special device with mirrors was used
|
| Maybe this: https://en.wikipedia.org/wiki/Blink_comparator
| comonoid wrote:
| No, a modification of this:
| https://en.wikipedia.org/wiki/Stereoscope
| 7bit wrote:
| I've done this on these game machines 30 years ago when I was 10.
| I'm baffled that there are still people who have to figure this
| out.
| timthorn wrote:
| This is effectively how Pluto was discovered (not cross-eyed, but
| with a tool to help):
| https://airandspace.si.edu/stories/editorial/finding-pluto-b...
| f0e4c2f7 wrote:
| Front page of HN. Funny to imagine thousands of people sitting in
| the office crossing their eyes at their computer screen right
| now.
| Fnoord wrote:
| All it did was hurt my eyes. I'll opt out of playing,
| superpower be damned.
| haswell wrote:
| I think the key is not "going cross-eyed" as much as it is
| relaxing your focus until the images merge. If you
| intentionally cross your eyes, it hurts. If you de-
| focus/relax your eyes until the images merge, it doesn't
| hurt.
| HaZeust wrote:
| Relaxing focus for me doesn't cause merging or cross-eyed
| effects, it causes my vision to go too blurry to do
| anything lol
| boogieknite wrote:
| i had the same thing where best i could get when i
| relaxed was a narrow merge, and when i crossed my focus
| was too close to my face to be helpful, plus strain.
|
| sudden clicked after fully crossing 5 or 6 times and then
| relaxing and was able to hold the "3rd image" very
| easily. felt like magic, even hardest difficulty was
| obvious
| Fnoord wrote:
| For me it just does not work right now. Maybe I have bad
| eyesight, I wear glasses and am past 40. I believe I was
| able to do this trick in past though. At the very least
| on psychedelics (various kinds). This also made me able
| to relax my eyes more, wheras I normally have too much
| pressure on them according to optician.
| Pxtl wrote:
| That's more for traditional "magic eye" pattern stereograms
| where you want to relax your eyes to look off into the
| middle distance _behind_ the subject instead of intensely
| focusing on something unnaturally close to your face.
| llm_trw wrote:
| I've used this to quickly read through a few hundred page
| documents given to us only as a scanned pdf which was too low
| quality to run ocr (at the time) on. The sleazy counter party was
| very upset when I came back with notes on them not adding the
| changes we asked for on the drafts they sent back within minutes
| of them sending them back.
| layer8 wrote:
| I can't parse your second sentence.
| whatshisface wrote:
| Uncross your eyes! :-)
|
| (They're saying that the person who send the contract was
| trying to trick them, and that they were upset when the trick
| was caught.)
| fragmede wrote:
| a counterparty is the other person you're signing a contract
| with who sometimes lies to you and says they changed things
| when they didn't
| layer8 wrote:
| It was the grammar I had trouble with, not the vocabulary.
| A comma before "within" would have helped a bit.
| jogu wrote:
| I remember doing this as a child on our TV that had a picture-in-
| picture setting. I would set the same channel twice and cross my
| eyes pretending that it was 3d TV.
| dylan604 wrote:
| How does that work when the two images are different sizes and
| overlapping? Did your PiP mode have a split screen option? The
| ones I've seen only allowed moving where the insert was placed
| (which corner), but it was always a PiP and never a split
| screen.
| jogu wrote:
| Yes, it had a split screen option where the two images were
| the same size and side by side. Can't recall what kind of TV
| it was... perhaps a Sony?
| foobarian wrote:
| It's a sailboat!
| kayge wrote:
| Hah, Kevin Smith caught some flak for that one:
|
| " Someone called out Kevin Smith for this on one of his
| podcasts. According to Smith, on the day of filming, he asked
| if the picture really was a sailboat, and the prop master said
| no. When Smith started questioning this, the prop master said
| that a) it flashes on the screen too quickly for anyone in the
| theatre to notice, and b) VHS was too low-resolution for people
| to freeze-frame it to try it at home. So Smith let it slide.
|
| Smith summed up, "Now, thanks to Blu-Ray, I get people pointing
| this out to me all the time!" "
|
| https://www.reddit.com/r/MovieDetails/comments/9lf52b/in_the...
| j3s wrote:
| all i managed to do was make myself very dizzy
| intalentive wrote:
| Validates a claim in the predictive processing paradigm. The diff
| between actual and expected is what matters to error correction.
| That's where all the relevant information is.
| valbaca wrote:
| Learned this at a young age with the Highlights magazines at the
| dentist.
| freecodyx wrote:
| I used to play this game with a friend when we were at the pub,
| once we start struggling spotting the differences we know we're
| drunk
| alfiedotwtf wrote:
| This is also how I used to do Magic Eye images when I was a kid.
| Although the stereoscopic image was inverted on the z axis, it
| was a lot easier than to cross eyes by looking further out into
| the distance
| unkulunkulu wrote:
| Hah, old trick, I read pull requests this way for years
| throw7 wrote:
| I always feel like I'll permanently see cross eyed if I keep
| doing that. It doesn't help that I was accidentally hit in the
| head by my double's partner racket in tennis and spent like a
| minute or two walking around seeing double. Not fun.
| belowm wrote:
| After a short period of training, I got to the point where I can
| see the third image which I can focus on. However, the
| differences are very subtile and don't stick out at all :/
| drdo wrote:
| Try the second test image (the one labelled "Hard", with the
| snow). That one was far easier for me than the first (the cat
| one).
| breadsniffer wrote:
| Wow. That's insane! With the trick I can somehow solve them all!
| error404x wrote:
| I tried crossing my eyes, but it's not working for me; I keep
| seeing things blurry. Maybe I'm doing it wrong. However, I solved
| the first two puzzles. For the last one, I just guessed randomly.
| My guess wasn't exactly correct, but it was close, just a little
| distance away.
| bootwoot wrote:
| One thing I noticed: because you're tricking your eyes into
| thinking they're observing at a different distance, your brain
| doesn't seem to correctly account for head tilt (my theory of
| the diagnosis). Anyway, I think you're head must be _exactly_
| level with the image or you 'll get double-vision/blur
| sdwvit wrote:
| It's way trickier if you have astigmatism
| evandrofisico wrote:
| Come on, I've been doing this since I was like 4 years old, this
| can't be news for anyone, Am i right???
| jeffhuys wrote:
| Yes, I didn't think people would be so amazed by it either.
| Like it's mind-blowing that this works or has been thought of.
| But we first did it once as well, some people just discover it
| late in life I guess (or not at all).
| manishfoodtechs wrote:
| I can overlap. But still need to match overlap with anyone.anyway
| interesting
| soperj wrote:
| Any recommendations for when you can't get the images to quite
| overlap? I feel like I can get 75% of the way there, but then
| they start going the other direction. I can do magic eye easily.
| kayge wrote:
| Use your browser to zoom out and make the images slightly
| smaller
| jasperry wrote:
| Claims have been made (outside the medical mainstream) that
| regularly practicing crossing your eyes helps stave off
| presbyopia. One does get better at seeing stereograms with
| practice, so it seems like it at least improves some type of
| muscle control.
| svilen_dobrev wrote:
| uh dunno.
|
| 25y ago, i was working behind a 30" tube monitor (a ~35kg hog),
| with 1 inch thick frontglass.. and one day, one of my eyes
| started to focus on the (closer)outside of the glass, the other
| on the (farther)inside of the glass. Could not shake that with
| closing/blinking. Worse, later, when i got into the car, the
| closer eye focused on the windshield - instead on the landscape
| ahead.
|
| Took 1 week of everyday 1-2 hours staring far away at the
| ocean, to revive. AND removal of the monitor :/
| jredwards wrote:
| Okay, but my eyes hurt now.
| nullbyte wrote:
| My Piano teacher used to have this book on her coffee table with
| images like this. You could blur and cross your eyes, and the
| image would combine to become 3D.
|
| But I never knew this technique could be used to spot the
| difference between images. Very cool discovery!
| ayeeyeiiieee wrote:
| ITT: everyone telling us their stories about how great they are
| at stereograms. We get it, you're all super special.
| rererereferred wrote:
| This is a game mechanic in one of the trials in Ace Attorney
| Chronicles.
| woah wrote:
| Do people not know about this?
| kiwiguy1 wrote:
| This is the coolest thing I have seen on here!!
| cyberax wrote:
| This trick had been used in practice to detect fake banknotes and
| coins, with a device like a two-sided periscope. It allowed a
| bank worker to put a real coin on one side and the tested sample
| on the other, so that any differences can be immediately
| apparent.
| iforgotpassword wrote:
| We got a magic eye book when I was maybe 6 - some time early
| elementary school. After learning how to do it, and also trying
| it by crossing my eyes to see an "inverted" image, I started
| doing it whenever I saw some repeating pattern IRL. It was most
| interesting when it was slightly uneven, for example a fence with
| sloppily applied vertical planks. Doing the magic eye would make
| it seem like some of them are closer to you than others.
| Eventually I tried the same on those "spot the difference" games
| since well it seemed kinda obvious to try, and I was blown away
| that it accidentally gave me that "superpower". I think that was
| pretty smart for a 6yo. Has only gone downhill ever since. ;-)
| xamuel wrote:
| I wrote a paper about doing this using human eyes as the
| "repeating pattern" (either someone else's, or your own in a
| mirror): https://philpapers.org/archive/ALEDSK.pdf ...You can
| use this trick to make boring meetings or conversations mildly
| more amusing (but be careful not to look like a clown crossing
| your eyes).
|
| If you're an expert at this, you can even do it to your own
| hands. Hold both hands in front of you but with one of them
| palm-away and one of them palm-toward you, so that they have
| the same shape, then cross- or parallel-view them to get an
| illusionary middle third hand. Walk around while focusing on
| the third hand and it's a seriously trippy effect.
|
| Another "super power" application similar to OP: the ability to
| confirm whether or not two distant digital clocks' seconds-
| digits are perfectly in sync. Since they're distant, it takes
| time to shift one's gaze from one to the other, making it hard
| to confirm whether they're in sync. But cross your eyes so as
| to reduce the distance, and voila.
|
| Yet another application: quickly assume the same head-tilt
| angle as your conversation partner. Suppose they tilt their
| head to the left by N degrees and you want to tilt yours the
| same way, how can you be sure you have the exact correct tilt?
| Easy: parallel-view their eyes (as described in the
| aforementioned paper). You will HAVE to tilt your head the same
| as them in order to see their "third eye" (and once you've
| locked on to their third eye, you can effortlessly adjust your
| head tilt as they do by using their third eye as the necessary
| guide)
| mensetmanusman wrote:
| Peak HN.
|
| Stereogramming your colleagues eyes during boring meetings.
|
| Ha
|
| Edit: I accidentally did something similar by imaging the
| crease on an N95 mask as a smile near their nose. It made
| them look like ducks and I had to bite my tongue so hard to
| not laugh. I could not unsee it.
| BenjiWiebe wrote:
| If you're distant enough / the people are sitting close
| enough, you can stereogram two people's faces together. You
| usually only get fleeting moments of crispness when their
| heads are aligned correctly though.
| xamuel wrote:
| Yep! If I knew someone IRL who was into this kind of stuff,
| I'd really love to experiment with this sort of thing and
| mirrors. Arrange so that you can stereogram your
| conversation partner's face with a mirror image of your own
| face (and that he can do the same with your face and a
| mirror image of his face). If anyone's in NYC and
| interested in these sorts of things, my email is in my HN
| profile "about".
| makeworld wrote:
| Wow I feel like I've never seen anyone talk about this. Doing
| it with fences can feel pretty magical, like the object is more
| "real" than other things.
| BenjiWiebe wrote:
| Or the side of a shopping cart.
| satvikpendem wrote:
| Now try it with various colors, some people can see
| "impossible" colors [0].
|
| [0]
| https://preview.redd.it/yaiyf2bi9aa31.png?width=640&auto=web...
| brailsafe wrote:
| Damn, it works exactly that well.
| seanssel wrote:
| I've tried this in the past without luck, but suddenly I can do
| it now after reading about the subtle "shimmer" effect. Very
| cool!
| svilen_dobrev wrote:
| half-off-topic..
|
| i have ~1 diopter shortsightness. Was less before, slowly going
| up. So screens are getting blurrier. Have glasses but still try
| avoid using them.
|
| If i put the (flat edged) TV remote control at about 10cm from my
| face so it horizontally shadows lower half of both eyes, i see
| perfectly (without any glasses).
|
| go figure..
| HaZeust wrote:
| It works for me like every tenth time I cross my eyes to look at
| a "spot the difference" picture. I don't know how it works for
| people instantly.
| lxe wrote:
| Instead of crossing your eyes and attempting to focus, what can
| really help relax your ocular muscles is to do the opposite: look
| "past" the images into the distance until the images overlap.
| adamc wrote:
| I couldn't do the cross-eyed thing, but it took me maybe 20
| seconds to spot the difference just by looking at sections of the
| images. But I'm not sure that would have worked had the missing
| bean been buried in the denser part of the photo.
| AlexandrB wrote:
| Some repeating tile patterns like stripes will cause my eyes to
| do this automatically and it's really weird and annoying because
| everything else gets blurry. Fun trick though.
| StevenNunez wrote:
| Jokes on you, my eyes don't work together so I can only see out
| of one at a time!
| ibeff wrote:
| There's dozens of us!
| claiir wrote:
| An alternative technique called "divergence" [1] (pulling your
| eyes apart) is significantly less straining on your eyes than
| crossing them ("convergence" [2]) while being equally as
| effective spotting differences, even on video. It's also what
| your eyes naturally do when you watch stereoscopic 3D with tinted
| glasses--the stereoscopic images are pulled _out_ (divergence)
| not pushed _in_ (convergence /cross-eyed). I've been doing this
| since I childhood. If you get good at it, you can watch side-by-
| side 3D videos in 3D with just your naked eye (e.g. VR)! I
| believe there's a reddit covering the more prurient variety of
| that.
|
| [1] https://en.wikipedia.org/wiki/Vergence#Divergence
|
| [2] https://en.wikipedia.org/wiki/Vergence#Convergence
| iamjackg wrote:
| This is what I do, the only issue is that I don't have nearly
| as much "range" with divergence as I do with convergence, so I
| have to make the pictures as small as possible when using it to
| line up two images (as opposed to autostereograms, which
| usually have a much smaller divergence offset).
| sirobg wrote:
| Do you have a training method for divergence?
|
| Similar to the finger moving closer and closer to the upper
| nose technique, for convergence.
| Pxtl wrote:
| It's a little more abstract since you don't have handy
| moving-reference-object like your finger, but: Place the
| picture in front of something deep, like a long hallway. Look
| off at something in the distance behind the picture, like the
| end of the hallway. Notice how the edge of the picture is a
| double image. Focus on _gradually_ resolving the edge of the
| picture down from double-image to single-image, and then do
| the reverse by looking down the hallway again and seeing the
| picture go back into double-vision. Just keep practicing that
| until you get the feel for controlling your depth perception
| and then try holding the same depth of the hallway while you
| turn your gaze to the picture and try the same action with
| your eyes.
| blipvert wrote:
| "Impossible mode" was the easiest for me - took a few seconds.
| Probably due to the aspect ratio and the size of the images on my
| phone screen.
| mannykannot wrote:
| This did not work for me. I was able to invoke a middle image,
| but there was no shimmering. After I found the difference the
| old-fashioned way, I realized that the middle image showed the
| distinguishing feature as it is on my non-dominant side.
| nixpulvis wrote:
| I can produce the third image by crossing my eyes, but one eye
| dominates and all I see is a cat with three stripes on its head.
| :(
| bluedino wrote:
| I have been doing this forever, if you get the high score over a
| certain threshold you can get a free game (400,000?)
|
| I would usually get accused of memorizing all the pictures.
|
| You will get bored or a headache before you stop getting free
| games using this technique.
|
| You can get stifled by the older machines with faded CRT screens.
| The newer LCD (that's how old these games are...) are usually
| better to play on.
| on_the_train wrote:
| The superpower being writing clickbait titles for trivial posts
| tarunkotia wrote:
| Image worked but when I tried with text it did not work. Is there
| some trick to it?
| marnett wrote:
| Woah that is amazing how quickly I was able to apply this.
|
| So cool!
| dathmar wrote:
| I was hoping to get a new superpower today, but when I was young
| I was cross eyed. I got this corrected through surgery and can no
| longer cross my eyes.
| CrimsonCape wrote:
| I have a true vision-based super power.
|
| my vision is so bad with nearsightedness that when I take
| corrective lenses off, I can focus on an ipad mini screen within
| 10" of my face and perceptually it is the same as focusing on a
| distant movie theater screen. No straining, eyes totally relaxed.
|
| With the lights off, it's better than being in a theater. I tried
| an ipad pro in the Apple store and it felt like I had my own
| personal unfairly huge IMAX screen.
| computerdork wrote:
| I have really bad vision too (my prescription is left: -8.00,
| right: -7.50). Tried this out, and yeah, really works! And
| realized, you need the best resolution screen possible, because
| you can see every detail. Not sure how much I'll use this is
| the future, but good to know it's always an option!
| boxed wrote:
| Natures own VR goggles.
| dsubburam wrote:
| Unlike when focusing on a movie screen, your eyes have to turn
| inward to direct the pupils to converge at the physically near
| iPad. This can cause muscular eye strain (it does for me).
|
| You can get clever and order a prismatic prescription that
| bends light out, so your eyes don't have to turn inward. I
| tried it too, but it gave me nausea.
| kevinsync wrote:
| I've got -7.5 myopia/nearsightedness in both eyes, with
| astigmatism. As a result, my eyes can easily go out of focus to
| do Magic Eye or this type of thing. The bonus superpower is, if I
| take my contacts out and get really close up on something, it's
| like I'm looking through a microscope; if I happen to have
| glasses on, sometimes I can also catch the light and focus in
| just the right way to further magnify what I'm seeing already
| zoomed in. In those instances I see whatever's reflecting through
| the glasses, so mostly eyelashes and skin/pores, but it's
| fascinating nonetheless. Can't see a damn thing beyond the tip of
| my nose without corrective lenses though LOL
| drumttocs8 wrote:
| Same vision, and I found it hard to do at first- but super cool
| when the image appeared crystal clear!
| uoaei wrote:
| I appreciate the sentiment but "overlay the images by crossing
| your eyes" receiving that kind of incredulous reaction is really
| funny and kind of sad for me. I hope it's just amateur
| editorializing.
| hyperthesis wrote:
| A parallel processor is you!
| hn_throwaway_99 wrote:
| There are some great examples and detailed explanations IMO of
| this general phenomenon in the book "How the Mind Works" by
| Stephen Pinker. It essentially discusses how your brain is doing
| statistical work to build the 3D model from these 2 stereoscopic
| images.
| null0pointer wrote:
| You can use this same technique to view glasses-less 3D
| (stereoscopic) images. It's also fairly easy to create your own.
| Take two photos but offset the camera lens by approximately eye-
| width. Open the image editor of your choice and place the images
| side-by-side. View the composite image cross-eyed and you are now
| viewing a 3D scene.
|
| Also worth noting there are 2 versions of this kind of cross-eyed
| focus depending on whether your eyes are focusing on a point in
| front of or behind the actual image. This determines which side
| the left and right eye images should go on in the composite. I
| find it easier to focus on a point in front of the images but IME
| most examples online are for focusing on a point behind the
| image.
| thwg wrote:
| Please stop using that RSS icon on your "Subscribe" button if you
| don't intend to provide an RSS feed.
| sirobg wrote:
| This is incredible! Works unbelievably well. Thanks for sharing!
| kazinator wrote:
| I found it almost instantly, which was by dumb luck.
|
| But in the following few moments, seeing two nearly identical
| photos side by side soon made me think of stereograms, since I'm
| into them, and have shot a few in my lifetime.
|
| I then used my eyes to overlap the images.
|
| In binocular overlapped view, the difference loudly draws
| attention to itself, because it flickers between the two eyes.
|
| It's almost as if there were a blinking LED saying "here it is!"
| smusamashah wrote:
| For anyone who wants to learn this, try this way using your
| finger as a helper.
|
| Put the images in front of your eyes.
|
| Bring your finger between your face and the image at almost
| middle of the distance.
|
| Now look at your finger.
|
| Move your finger back and forth and notice the background (where
| your picture is)
|
| While doing this, notice that at a particular distance, the
| images in background will perfectly overlap each other.
|
| That's your moment.
|
| Pull out your finger and look at that image.
|
| --
|
| It worked on everyone I have tried to teach. You may always need
| help of your finger or a tip of a pencil or whatever. But it's
| lot easier to get those images to merge this way.
| skeaker wrote:
| My eyes seem to immediately refocus as soon as my finger moves
| away no matter how many times I try this. Before I move my
| finger away, everything in my peripheral vision is too blurry
| to be useful.
| dusted wrote:
| I that not the entire point with those "find the difference"
| pictures? To teach kids how to do just this ?
| sneak wrote:
| I was able to do it for the first time after reading this webpage
| with the technique, cool!
| mjal wrote:
| Nice to see someone discover this! I've always been partial to
| spot the differences and crossview images - I am able to cross
| each eye independently of one another, which makes overlapping
| these sorts of images very easy. For example, I could cross my
| right eye, while my left stays perfectly still. This causes
| instant double vision, and relaxing how crossed the eye is lets
| me line the images up very quickly. It's fun to do in places with
| a repetitive wall texture, too - seeing something in real life
| while adding a faux 3D effect on top of it is kind of trippy.
| Probably my most useless skill, but a fun one regardless.
| theginger wrote:
| Is the technique to this exactly the same as the technique to
| view a 3d stereogram image?
|
| I was able to get a 3rd image to be clearly visible in the middle
| doing this, on the 2nd image I could definitely seem some spots
| appear that lead me straight to 3 of them but didn't work for me
| on the other 2 images.
| Pxtl wrote:
| The left-right full-image stereograms... but those are less
| common than the pattern-based "magic eye" stereograms. Those
| are the reverse of this - in the linked image and the left-
| right full-image stereograms, they're done by crossing your
| eyes to a point _closer_ to your eyes than the original image.
|
| The pattern-based "magic eye" stereograms are done by looking
| through the image to focus on a point deeper into the screen
| _further_ from your eyes.
|
| The latter I think are less painful because they use the more
| natural depth-perception distances of your eyes instead of
| using what feels like more unnatural positions, but that might
| be my bias because I'm a bit farsighted. Maybe they're just
| more common because they're visually inscrutable at first and
| so you get the "reveal" of the 3D contour from a single large
| image instead of two already-visible small ones.
| amingilani wrote:
| I'm frequently surprised by the amount of seemingly ordinary
| skills I picked up as a bored child that other people didn't.
| This was an obvious way to solve those "spot the difference"
| pictures in magazines.
|
| I wonder what skills other people picked up that I didn't.
|
| Some recent example of things I shared:
|
| + When your belt buckle hangs a little loosely on the front of
| your pants. You can hook the buckle's prong onto the front button
| of your pants and it'll stay put. So many people are excited to
| learn this.
|
| + Putting a jacket or any open-front garment on quickly. I saw
| someone struggling to maneuver their second arm in a tight jacket
| behind their back. I explained that if they hold their jacket out
| in front of them, put their hands in the arm holds, and slide
| their arm in further as they swing it around their body they'll
| get it on in a moment. It's also more stylish. They were so
| surprised.
| xamuel wrote:
| Ear rumbling: https://www.reddit.com/r/earrumblersassemble/
|
| Eye shaking: https://old.reddit.com/r/Eyeshakers/
|
| Some of us are born with small frenula of the tongue (or we
| undergo tongue-tie surgery as kids) and can thus perform
| Khecari mudra without the traditional self-mutilation used by
| yoga-masters.
| https://en.wikipedia.org/wiki/Khecar%C4%AB_mudr%C4%81 This can
| be useful for cleaning tonsil stones or post-nasal drip, but of
| course you must do so discretely since people would consider
| that absolutely disgusting
|
| If you want to read out loud for long stretches of time and you
| hate taking breaks to catch your breath: you can read out loud
| while inhaling too! (It feels and sounds super weird though so
| this isn't very useful in practice.)
|
| And here's a party trick related to OP's super power. Pick a
| distant object and cross your eyes so as to see it double,
| preferably with the two doubles distant from each other (i.e.,
| cross your eyes significantly). Then, alternately switch
| between staring at the left double, and the right double. If
| you do it right, it will look like your eyes are moving in a
| bizarre alien way.
| kdmtctl wrote:
| > When your belt buckle hangs a little loosely on the front of
| your pants. You can hook the buckle's prong onto the front
| button of your pants and it'll stay put. So many people are
| excited to learn this.
|
| Yep. And there is a special vertical prong keeper tab on some
| trousers for exactly this purpose.
| TeMPOraL wrote:
| > _I 'm frequently surprised by the amount of seemingly
| ordinary skills I picked up as a bored child that other people
| didn't. This was an obvious way to solve those "spot the
| difference" pictures in magazines._
|
| Conversely, I'm amazed by the amount of things I discover as an
| adult are _not_ common experiences or skills for people,
| despite being considered as such. This includes, for example,
| having an inner voice (which I do), or ability to visualize
| things in your head (which I _don 't_).
|
| Wrt. the latter, when I learned as an adult that some people
| actually _can_ conjure up images in their mind on demand[0],
| and conversely that aphantasia is a thing, it took me few more
| years to connect that back to some early experiences in
| childhood - being bored out of my mind by some well-known
| novels that my parents and teachers found particularly
| engaging. Specifically, the ones rich in descriptions of
| scenery. They 'd say that's the best part, what makes the story
| rich and immersive, and that's what imagination is for and
| those books are good for exercising it. Meanwhile, I'd feel
| ashamed and wonder what the fuck are they talking about, while
| skimming to find where the descriptions end so I can resume
| reading from there. Well, it turns out what they said was true
| _for them_ , but is not true for people like me, who can't
| visualize to save their life.
|
| Well, except in dreams. Which makes the whole thing even more
| fascinating.
|
| > _Some recent example of things I shared:_
|
| Interesting. I somehow managed to never learn either, so
| thanks! Ironically, I realize now I've probably seen people do
| the jacket swing trick hundreds of times, and yet it never
| registered in my mind as a distinct technique, much less one
| that I could learn.
|
| --
|
| [0] - Fun fact: that makes "undressing someone with your eyes"
| a literal ability for them too.
| altgeek wrote:
| Stereograms have been used in structural biology publications for
| many decades now. Google 'stereogram structural biology'
| tristramb wrote:
| I've been using this to do quick source code diffs for years. I
| started back on the days of printouts.
| athom wrote:
| Easily defeated by arranging the images vertically.
|
| Or at least, makes it a LITTLE bit harder.
| sota_pop wrote:
| Wonderful! with your write-up, I was able to "see".
| pbhjpbhj wrote:
| I've always thought that ability to unfocus the eyes might be
| related to mental focus. If you have difficulty staying on topic,
| or a diagnosis of ADD/ADHD or whatever {I'm not equate these} AND
| find it really hard to do magic eye images... Then please take
| part in my 'totally scientific study'TM.
| pbhjpbhj wrote:
| Upvotes, I agree, I have mental focus issues and can't do magic
| eye (upvote)
| pbhjpbhj wrote:
| Downvotes, I disagree (downvote)
|
| {I should have done an actual survey, sorry; felt cute might
| delete.}
| pbhjpbhj wrote:
| I have mental focus problems, magic eye is easy for me.
| (downvote)
| dalemyers wrote:
| I'm amazed that there's so many comments and yet not a single one
| is pointing out that the coffee bean is missing from the _right_
| side of the image. Not the left.
| dabber21 wrote:
| Wait, this is news? that's how I always solved those puzzles, I
| thought everyone did that
| rahimnathwani wrote:
| I find it very easy to overlap images, I think because of the eye
| exercises I had to do as kid.
|
| I don't recall what these exercises were for, but there were two:
|
| 1. Stare at this image of two incomplete cats, and merge them
| together into a single complete cat:
| https://www.google.com/search?q=eye+muscle+cat+card
|
| 2. This strip of cardboard has a number line on it. Put one end
| half way down your nose, perpendicular to your face. You will see
| two lines. Merge them at their furthest point, then merge the
| next nearest point, repeat. (I think this is called the 'Brock
| String Exercise', but can't find an image similar to the one I
| recall.)
| luxuryballs wrote:
| yep it's just like those magic eye pictures that were big in the
| 90s, once you learn how to see those instantly you can do this
| trick also
| hprotagonist wrote:
| Good old vdiff: https://catb.org/jargon/html/V/vdiff.html
|
| _Visual diff. The operation of finding differences between two
| files by eyeball search. The term optical diff has also been
| reported, and is sometimes more specifically used for the act of
| superimposing two nearly identical printouts on one another and
| holding them up to a light to spot differences. Though this
| method is poor for detecting omissions in the 'rear' file, it can
| also be used with printouts of graphics, a claim few if any diff
| programs can make. See diff.
|
| An interesting variant of the vdiff technique usable by anyone
| who has sufficient control over the parallax of their eyeballs
| (e.g. those who can easily view random-dot stereograms), is to
| hold up two paper printouts and go cross-eyed to superimpose
| them. This invokes deep, fast, built-in image comparison wetware
| (the same machinery responsible for depth perception) and
| differences stand out almost immediately. This technique is good
| for finding edits in graphical images, or for comparing an image
| with a compressed version to spot artifacts._
| JeremyHerrman wrote:
| To really blow peoples' minds use both hands to tap the
| differences, keeping the left hand for the left image and the
| right hand for the right image!
|
| From your POV the images are merged so your hands will look like
| they're tapping a single image, but from the audience's point of
| view you look like a savant with multi-attention!
| leecarraher wrote:
| i certainly used this trick back in my college days, prompted by
| a similar technique for "seeing" 3d stereoscopes on a computer
| monitor. I feel like i learned it somewhere on Eric Weisstein's
| Mathworld because the 3d objects viwer app let you split the
| image into two stereo images. Unfortunately java applets have
| been banished from the internet landscape.
| Balgair wrote:
| You can also use this to display 3-D images. You have a
| stereographic projection of your image (like those kids' view-
| masters) and then just cross the eyes and look at the middle
| image. Only since the 2 images are slightly different, you can
| have the middle image be 3-D. It takes a bit of practice though
| and causes eye strain (at least for me)
|
| It's not a great way of showing the image, but it'll do in a
| pinch.
| scrozier wrote:
| I spent weeks doing this, looking at stereoscopic (?) images of
| protein structures, while a grad student in molecular biophysics.
| I got so that I could see the overlapped images pretty much
| instantly. But I'm having a hard time getting it now, even on the
| easy one.
| javaskrrt wrote:
| okay, this is so cool. thank you for the new superpower!
| modzu wrote:
| and now my eyes are stuck this way forever
| mads_quist wrote:
| Fuck it does work...
| emh68 wrote:
| Wow! It really works. The missing bean "pops" out at you. The
| hardest part is getting your brain to focus on the cross-eyed
| virtual center image.
| grishka wrote:
| This whole "just cross your eyes" thing has never worked for me,
| not once. I've seen these strange patterns printed on the backs
| of notebooks that supposedly make some sort of 3D effect when you
| "just cross your eyes". Later, when I saw similar images online,
| I was able to at least visualize these hidden shapes by opening
| the image in photoshop, duplicating the layer, setting the copy
| to "difference" and moving it left or right. The regular texture
| would eventually disappear and the shape would emerge. It's still
| a mystery to me what it feels like to view these the intended way
| though.
| titzer wrote:
| Here are some tips;
|
| 1. When you cross your eyes, gradually let them return to
| uncrossed. Try to do it as slow as possible. Along the way, try
| to line up any structures that you see in the image that are
| repeated from left/right half.
|
| 2. Once you are able to hold a cross-eyed gaze long enough with
| lined up left/right half, slowly move your eyes between
| different features near the middle. Your eyes will naturally
| want to start to focus and match up pieces.
|
| 3. Don't be too far or too close to the image; they are usually
| easily viewed from comfortable distances. If the image is too
| big, make it smaller. It's usually easier smaller.
|
| 4. Initially, when you cross your eyes, or look through the
| image, it will likely be blurry. This is because your brain
| naturally associates accomodation and convergence with also
| changing focus. You'll learn to decouple those things and you
| will more quickly be able to go from focusing on the 2D image
| to crossing it without changing focus much.
|
| There's a whole bunch on this site:
| https://www.magiceye.com/stwkdisp.htm
| ndxf wrote:
| Doesn't work for me either. I just made myself queasy while
| trying to cross my eyes for ten minutes haha
| mplanchard wrote:
| I've also always had a hard time with these. I suspect it's
| because one of my eyes was slightly lazy when I was a child, so
| my brain learned to put more importance on the signal from the
| other eye. When I cross my eyes, the image from the better eye
| tends to just totally override the other one, so it can be
| really hard to see these kinds of effects.
| davejohnclark wrote:
| I have exactly this as well. My optician explained it as my
| brain would use the information from the lazier eye only if
| there wasn't any information from the good eye. Just tried
| the eyes crossed trick on the easy image in the article and
| the 3rd image in the middle is the right one. If I let them
| drift apart so there are 4 images I can see the left one and
| the difference (because I'd already found it), but as soon as
| I force them to overlap the left signal disappears and I'm
| only seeing the right image. I've also never managed to do a
| magic eye or anything, and 3d movies just give me a headache.
| fonema wrote:
| Same here, but I always imagined that for it to work, I would
| need to have roughly equal vision in both eyes, which I don't.
| Everything is blurry with my left eye, and no glasses or lenses
| have ever helped. I attribute this as the reason.
| guico wrote:
| This is exactly why I read HN
| jon309 wrote:
| This does not work even in the slightest. When I cross my eyes,
| the image becomes wayyyy too blurry and its hard to keep it in
| the center for more than a second
| tessellated wrote:
| That's how I used to help my grandmother when I was a little
| child. She always used to remark that the last one (5th) was the
| most difficult to find.
| sailfast wrote:
| This whole time it's been a Magic Eye problem? Geeeeez. This
| would've won me so many random challenges over the years.
| y-c-o-m-b wrote:
| Well this is interesting. I was able to find the impossible one
| within 2 seconds without crossing my eyes. The easy one took
| about 5 seconds, 3 seconds for hard. I've always been hyper-
| vigilant with patterns (to a fault), so not sure if that's
| playing into this.
|
| Is that what other folks are experiencing also? I see most
| comments are trying it with their eyes crossed, but what about
| without?
|
| EDIT: ok I just watched the video. No eyes crossed. For the
| balloons one I beat out the girl in the video by 2-3 seconds. For
| the birds about the same. The skittles one tripped me up,
| couldn't find it. The other few I found around the same time, the
| lights at the end I didn't find in time either. It seems I'm
| quicker when there's not too many colors involved. Still that's
| spooky.
| mmh0000 wrote:
| There's a video game of this called QuickSpot. Back in 2008, this
| was one of my favorite games for the Nintendo DS. It trains the
| ability to spot little differences quickly. Sadly, outside of
| winning a barely known video game, it's not a super useful skill.
|
| https://en.wikipedia.org/wiki/QuickSpot
| ChildOfChaos wrote:
| I can't seem to do this, it seems impossible for me to cross my
| eyes. Hmmm.
| lobo_tuerto wrote:
| This is exactly the same skill needed to see 3d pictures (aka
| autostereograms).
| s4i wrote:
| Almost certainly a lot of the people saying they are "crossing"
| their eyes are actually "uncrossing" their eyes; focusing the
| eyes straighter than what would normally happen on the surface
| where the image is laid out.
|
| This is also how the legendary "Magic Eye" books were supposed to
| be viewed. Not by crossing the eyes.
| Imnimo wrote:
| I can get the overlap to lock in, but the simmering effect is
| weak and difficult to pick out. Probably still faster than
| exhaustive search, but I don't feel like I'm at superpower level.
| Maybe my brain favors one eye more than the other? I know I have
| different glasses prescriptions for each eye.
| topspin wrote:
| It tried just after waking up, using my phone's screen, and it
| worked immediately. Not exactly a pleasant thing to do, but it
| does work as described.
| labanimalster wrote:
| Learned it from Magic Eye books too! But using it for spot-the-
| difference is way more practical - saves so much time compared to
| staring at two pictures. Kind of feels like having X-ray vision
| for finding differences
| abotsis wrote:
| I have strabismus and have always been good at these games. I
| wonder if it helps me for similar reasons? The examples on his
| page were pretty easy for me, though the universe one took maybe
| 45 seconds.
| rahulvarshneya wrote:
| This is just incredible!
| PUSH_AX wrote:
| A ton of comments in here saying this is easy/old hat for them.
|
| Well I'll be the one to say this blew my mind. somehow creating
| the third middle image, being able to relax my eyes and even scan
| around this composite image actually made me giggle out loud on
| my laptop, a very rare occurrence. Thank you to the author.
| EVa5I7bHFq9mnYK wrote:
| Using this trick, I wrote a program for 3d plot visualization in
| the 80-s. It computed two projections of the plot, as if looked
| by left and right eye, and printed them side to side on the
| thermal printer. If you looked hard enough, you can bring the two
| pictures together and see a 3d picture!
| Slow_Hand wrote:
| This trick is interesting to me as someone who mixes records. I
| (and mixers in general) have a lot of different tricks for making
| mono audio objects in the mix feel stereo or have a sense of
| width or depth.
|
| Examples include:
|
| 1. Delaying the left or right channel by a few ms (Haas effect).
|
| 2. De-tuning one of the channels by a few cents
|
| 3. Boosting an EQ band on one channel, with a complimentary cut
| on the opposite channel.
|
| ...and many more.
|
| These are usually very subtle changes that our stereoscopic ears
| have no problem detecting.
|
| In any case, when we need to do some forensic searching for
| possible differences between two near-identical channels we'll
| invert the polarity on one channel and then sum them. The
| resulting delta sticks out like a sore thumb and highlights even
| then tiniest differences between the files.
|
| So it's fascinating to discover that we can easily do something
| similar with our eyes to find the differences.
| simplicio wrote:
| Feel like people who are old enough to remember that 6 week
| period in the 90's where those Magic Eye 3d Stereogram pictures
| were everywhere have a big advantage here.
| shkkmo wrote:
| I cannot do this by crossing my eyes (focusing on a point between
| you and the image), I have a hard time getting the cross to stay
| consistent and it never really "locks in" for me. Instead of
| crossing my eyes, I unfocus them, effectively look through the
| image. Once I get the repeating part to overlap cleanly, after a
| second or two, my pupils adjust their focus and the image fades
| from blurry to clear in a really satisfying way and kind of
| "locks in" in a way that takes little to no effort to maintain.
| With a bit of practice, I can even move my eyes around and look
| at different parts of the two overlayed images without
| distrupting the effect at all.
|
| I don't know if it's just my brain working differently or if a
| there is some confusion in the discussion between crossing your
| eyes and focusing through an item.
| JoeOfTexas wrote:
| Wife was not impressed. That hit home haha.
| codefoster wrote:
| I didn't spend the time reading the comments to see if this has
| been said already, but crossing your eyes works but learning to
| diverge your eyes is better in some situations. It's easier to
| learn to cross because you can just look at your nose, and you
| can bring together two images that are further away by crossing
| than by diverging. But diverging is the way we are normally (when
| looking across the room say instead of at a book in front of us)
| so it's more comfortable.
| cal85 wrote:
| Interesting, what kind of situations does it come in handy?
| netman21 wrote:
| As a kid I learned to see stereograms in 3D by crossing my eyes.
| Exact same technique. Comes in handy for Mars images today.
| dionian wrote:
| I've never been able to 'lock' the two images together like this
| with my eyes focus. That was incredible.
| GMoromisato wrote:
| As I understand it, Magic Eye stereoscopic images were originally
| developed by brain scientists studying how we see in 3D (i.e.,
| how the brain processes 2 eye inputs into a 3D image).
|
| There were two competing theories:
|
| 1. The brain first does a recognition pass (that's a house,
| that's a person, etc.) and compares the two eyes to see which
| objects have moved.
|
| 2. The brain compares the two eye inputs first, at the "pixel"
| level and figures out which pattern of pixels has moved, then
| afterwards, applies recognition to the resulting 3D image.
|
| Magic Eye would only work if #2 is the correct theory (because in
| Magic Eye, there is nothing to recognize until AFTER you convert
| to 3D).
| TeMPOraL wrote:
| 1. Get a bit closer to the screen so you can see both images
| clearly.
|
| 2. Now, cross your eyes and aim to overlap both images.
|
| 3. Draw the rest of the fucking owl.
|
| Seriously. Ever since my physics teacher in high school tried to
| get the class interested in stereograms, everyone and every
| article I see talking about it treat "crossing your eyes" as an
| atomic, trivial step. It isn't. I for one have no first clue how
| to do it, it's not a distinct operation I know how to perform.
| Perhaps this is because I am nearsighted and wear glasses.
|
| Still, I wish articles like these focused on explaining how to do
| the whole cross-eye thing, because once you master _that_ ,
| everything else becomes instantly self-apparent and doesn't need
| further explanation (I know because I _did_ manage to
| accidentally cross my eyes once or twice while looking at a
| stereogram, so I know how the effect looks like).
|
| EDIT: FWIW, I compensate by using another trick for diffing
| documents with Mark I Eyeball - get them printed on separate
| pieces of paper, put one on top of the other, and hold in front
| of you with some bright light behind you (Sun, or your phone's
| flashlight, will do). Not as good as crossing your eyes, but
| something I can reliably do.
| z3t4 wrote:
| You can also use this method to watch 3d movies without vr
| googles.
| srinathkrishna wrote:
| Wow! That was amazing!
| justinl33 wrote:
| human stereo vision processing has incredibly sophisticated noise
| filtering capabilities that are still hard to replicate in
| software. The shimmering effect people report is essentially your
| visual cortex highlighting areas where the stereo correspondence
| fails.
| calebm wrote:
| Super cool. It works for me. I love magic eye stuff.
| jrmylow wrote:
| The most mind-bending example of the magic eye effect I've found
| is people using it in videos.
|
| Of course, the internet being what it is, someone made a version
| of Bad Apple with it: https://www.youtube.com/watch?v=RLuGJGyCS90
| rsktaker wrote:
| That's amazing! Within 40 seconds I overlapped the two hard mode
| images and saw 8 shimmering objects set within a clear picture.
| It took me a little longer (maybe a minute), but the two
| impossible mode pictures snapped together and I saw a single
| shimmering star within an otherwise crystal clear photograph!
| tlhunter wrote:
| It blows my mind that every human doesn't know this. I figured it
| out as a child. The easiest way to prevent this is to have one of
| the two images be slightly tilted. I can rotate my eyes but it's
| much harder than crossing them.
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