[HN Gopher] Blue light filters don't work - controlling total lu...
       ___________________________________________________________________
        
       Blue light filters don't work - controlling total luminance is a
       better bet
        
       Author : pminimax
       Score  : 81 points
       Date   : 2026-02-20 18:14 UTC (4 hours ago)
        
 (HTM) web link (www.neuroai.science)
 (TXT) w3m dump (www.neuroai.science)
        
       | snet0 wrote:
       | But have you considered that it _feels_ better?
        
         | stronglikedan wrote:
         | so do placebos
        
           | kurthr wrote:
           | I agree for sleep. I prefer them because they focus better
           | for me.
           | 
           | Blue creates a halo around letters that is distracting with
           | my declining vision.
           | 
           | Also, Blue fluorescent OLED are ~50% less efficient than R/G
           | phosphorescent OLED so you can reduce screen power
           | consumption of a full white page by almost 30% using such a
           | filter. That in turn might be 30% of active device power
           | consumption (for a total of almost 10% in battery life during
           | active operation). Ignoring that they also tend to burn out
           | more quickly, since tandem blue has become fairly mainstream.
           | 
           | Many more reasons for these "filters", if you don't mind the
           | white balance shift and reduced color gamut.
        
           | snet0 wrote:
           | So what? If I could take a sugar pill that guaranteed I feel
           | comfier looking at my screen, nobody can tell me it "doesn't
           | work". I'm not trying to optimise my life, I'm trying to have
           | my eyes feel better.
        
             | Barbing wrote:
             | Placebo and "manifesting"--the latter sounds mockable but
             | pretty much the same thing, harmless if helpful so hey!
        
               | nickthegreek wrote:
               | The placebo effect is a real, measurable mind-body
               | response where belief & expectation can change your
               | symptoms or how you feel. However, it does not directly
               | alter external reality. Manifesting claims your thoughts
               | or intentions can cause _outside events_ to happen, which
               | has zero evidence to support it.
        
               | mikkupikku wrote:
               | If somebody is "manifesting" themselves a sleep aid, I
               | think they'd just call it meditation and everybody would
               | more or less accept that it probably works for that
               | individual. Maybe you'd have a few people with severe
               | autism who start arguing on online forums about the
               | scientific evidence behind meditation, but that's just
               | them being them.
        
           | tshaddox wrote:
           | Not really. Most of the cultural notion about the remarkable
           | effects of placebos came from flawed studies in the 1950s. As
           | far as I can tell, the modern consensus is that there's no
           | clinically significant placebo effect _except_ for conditions
           | that can only be measured by a subject self-reporting their
           | own perception (like pain and fatigue).
        
           | allthetime wrote:
           | and? placebo is often effective.
        
       | debo_ wrote:
       | > Everybody wants better sleep
       | 
       | Bro, as someone who had brutal insomnia for a couple of years and
       | now sleeps "normally" for whatever that means, I can tell you
       | that I don't think about my sleep quality at all. I'm happy to be
       | sleeping.
       | 
       | If you too sleep "ok" for whatever that means, maybe stop
       | worrying about optimizing it and go do something else less
       | insane.
        
         | loloquwowndueo wrote:
         | What did you do to tackle your insomnia?
        
           | smt88 wrote:
           | Primary, idiopathic insomnia doesn't really exist. It's
           | almost always anxiety, although a few other mental and
           | physical conditions can also cause it. But more likely
           | anxiety.
        
             | debo_ wrote:
             | That was my experience as well.
        
           | m3047 wrote:
           | Disturbed sleep / inability to settle / anxiety can have
           | physical causes although these are poorly recognized /
           | diagnosed by regular allopathic medicine where I live.
           | 
           | Anecdata: 1) A good friend whose anxiety was largely
           | alleviated (and sleep improved) by recognizing and treating
           | their iron deficiency. 2) I have to (can't take the Western
           | drug which was prescribed any more, and the Western doctors
           | can't seem to bang the rocks together) take herbs for my
           | hypertension but as opposed to the side effects I was
           | experiencing from the drug I joke that all of the "side
           | effects" from the herbs are good, they're targeting
           | imbalances which were not recognized / treated previously and
           | lo and behold I settle and sleep better... which helps reduce
           | the blood pressure.
        
             | debo_ wrote:
             | Which herbs do you take?
        
           | debo_ wrote:
           | I spoke about it in this video:
           | https://www.youtube.com/watch?v=QnNPRqLVtaM
        
         | nine_k wrote:
         | Waking up tired and with the brain full of fog is nearly as fun
         | as not sleeping and ending up tired, with the brain full of
         | fog. Truth be told, most cases of "poor sleep quality" are not
         | as brutal though.
        
         | kqr wrote:
         | The charitable reading of "better sleep" is "sleep habits that
         | allow for a healthy amount of sleep". A lot of people have
         | habits that give them insufficient sleep.
        
           | jerlam wrote:
           | Yeah, "get better sleep" is usually followed with "by buying
           | this thing". No one makes any money if you go to sleep
           | earlier.
        
           | debo_ wrote:
           | My experience is being surrounded by people who sleep eight
           | hours a night and then check their ring data or whatever
           | nonsense to convince themselves that they could do better.
        
       | koalacola wrote:
       | Is this your article OP?
        
       | aethrum wrote:
       | They absolutely help my eyes not be so strained. If its placebo,
       | its a working placebo.
       | 
       | >Are people actually using Night Shift? >Aggravatingly, yes.
       | 
       | What is the authors problem lol? It feels a lot better on
       | eyeballs to use warm light things. Why does he care?
        
         | thenewnewguy wrote:
         | I'm not an MD or expert in this field enough to know if OP is
         | right or wrong, but I think it's fairly reasonable to be
         | irritated people are claiming software has a health benefit
         | based on vibes/feels.
         | 
         | I thought we as a society had moved on from superstition to
         | evidence-based medicine, but in this very post there are plenty
         | of replies countering OP's scientific analysis and data with
         | anecdotes (which is disappointing regardless of if TFA is
         | correct or incorrect).
        
           | geoduck14 wrote:
           | >I think it's fairly reasonable to be irritated people are
           | pushing software based on vibes/feels.
           | 
           | You are going to HATE to find out about night-mode in the
           | browser
        
             | thenewnewguy wrote:
             | To be fair, I should have said something like "claiming
             | software has a health benefit based on vibes/feels". I
             | personally prefer the look of night/dark mode (or whatever
             | you call it) in apps and the browser, but I'm not going to
             | claim it makes me healthier or improves my sleep or
             | whatever.
             | 
             | If you just like how something looks, that's fine, but
             | there's a difference between "I like how X looks"
             | (subjective opinion) than "X helps me sleep better"
             | (difficult to prove but objectively true or false).
             | 
             | Edit: Changed this in my original message as it seems
             | multiple people got confused by my prior poor wording.
        
               | thatcat wrote:
               | It's not about how it looks aesthetically, you can feel
               | your eye muscles release tension when you go from light
               | to dark mode.
        
               | IAmBroom wrote:
               | As someone more trained in science than software, the
               | phrase "you can feel..." is suspicious, _even if_ it 's
               | my own feelings.
               | 
               | Not invalid; suspicious.
        
               | 0x1ch wrote:
               | End of the day, dark mode would've been totally ignored
               | if there wasn't a perceivable benefit, placebo or not.
               | People want to make everything difficult, I guess.
        
           | jack_pp wrote:
           | Is it superstition to deduce that I get gassy after eating
           | beans? I need a scientific study to tell me this? Same for if
           | a screen hurts my eyes (not long term, like truly my eyes
           | hurt) when using bright white colors at night.
        
             | thenewnewguy wrote:
             | Yes, actually, if someone has direct scientific evidence
             | contrary to the claim (I doubt such evidence exists for
             | your first example as to the best of my knowledge the
             | relationship between beans and gastrointestinal changes is
             | well understood).
             | 
             | Your eyes could hurt for a variety of reasons - brightness,
             | too long screen time, being dry for external reasons, etc.
             | Most humans are poor at identifying the cause of one-off
             | events: you may think it's because you turned on a blue-
             | light filter, but it actually could be because you used
             | your phone for an hour less.
             | 
             | That's why we have science to actually isolate variables
             | and prove (or at least gather strong evidence for) things
             | about the world, and why doctors don't (or at least
             | shouldn't) make health-related recommendations based on
             | vibes.
        
               | jack_pp wrote:
               | It's pretty clear, even on monitor, night and day
               | difference at a push of a button. I'm not arguing if this
               | helps you sleep better but it is pretty arrogant of you
               | to tell me I can't figure out from my own experience if
               | something is comfortable or not.
        
               | BobaFloutist wrote:
               | Nobody really cares if it's comfortable or not _for you_
               | , the debate at hand is whether it's measurably more
               | comfortable for _the population at large_.
        
               | cgriswald wrote:
               | That's how it _should_ be but the poster is literally
               | calling the individual experiences of others
               | "superstition" based on _the population at large_.
        
               | nandomrumber wrote:
               | It's about the equivalent of someone claiming my saying I
               | find woollen clothing directly touching my skin to be
               | irritating / itchy requires double blind randomised
               | controlled studies to determine whether this is true at
               | the population level.
               | 
               | There are eight billion of us, we can't _all be
               | different_ , there must be at least some categories we
               | can't be sorted in to, maybe those who find woollen
               | clothing itchy and those who don't, and those who find
               | blue-light reduction more comfortable and those who
               | don't.
               | 
               | One of my pet theories is that this hyper fixation on The
               | Ultimate Truth via The Scientific Method is what happens
               | when a society mints PhDs at an absurd rate. We went up
               | with _a lot_ of people who learn more and more about less
               | and less, and a set of people who idolise those people
               | and their output.
        
               | crazygringo wrote:
               | > _if someone has direct scientific evidence contrary to
               | the claim_
               | 
               | Except they don't. This is evidence about _one_ potential
               | mechanism. Not evidence saying there are _no other_
               | potential mechanisms.
               | 
               | This is actually a very common mistake in popular science
               | writing, to confuse the two.
        
               | wat10000 wrote:
               | If your eyes routinely hurt when doing something, and
               | then they stop routinely hurting after you make a change,
               | that's pretty good reason to believe that there's a
               | causal effect there.
               | 
               | Sometimes the causality is clear enough that you don't
               | need sophisticated science to figure it out. Did you know
               | that the only randomized controlled trial on the
               | effectiveness of parachutes at preventing injury and
               | death when jumping out of an airplane found that there is
               | no effect? Given that, do you believe there really is no
               | effect?
        
           | bob1029 wrote:
           | > I think it's fairly reasonable to be irritated people are
           | pushing software based on vibes/feels.
           | 
           | https://en.wikipedia.org/wiki/Video_game_industry
        
           | taco_emoji wrote:
           | > I thought we as a society had moved on from superstition to
           | evidence-based medicine
           | 
           | Surely you didn't actually believe that unless you JUST
           | landed here from space after being away for 60 years.
        
         | KaiserPro wrote:
         | because if you read the article its about blue light filters
         | _to aid sleep_ not ease of reading.
         | 
         | The the grift wheel on this particular bandwagon is strong. To
         | the point where my fucking glasses have a blue filter on them,
         | which fucks up my ability to do colour work becuase everything
         | is orange.
        
           | robinsonb5 wrote:
           | If you wait long enough cataracts will give you that for
           | free.
        
           | cpburns2009 wrote:
           | Blue light filtering lenses come at a premium. You don't
           | accidentally get them.
        
             | KaiserPro wrote:
             | I wasn't paying for them, so it was very much accidental.
        
               | pavel_lishin wrote:
               | Someone ran up to you and put them on your face?
        
               | mikkupikku wrote:
               | You should go back and demand they be replaced. Such a
               | mistake isn't something you should tolerate.
        
         | tartoran wrote:
         | I confirm that this helps me as well. Quite often I don't have
         | any fancy filter, I'm permanently setting display/monitor to
         | low temperature and my eyes/vision couldn't be happier. I don't
         | even need darkmode, regular mode works just fine for me as long
         | as blue light is toned down. Granted, I'm not doing any color
         | correction or anything color sensitive work.
         | 
         | I used to have terrible headaches about 20 years ago when I
         | started spending a lot of time in front of the screen. I went
         | to an optometrist who tested my eyes and told me I could get
         | low prescriptions (.5) but warned me that there's no way back
         | and that many people are fine with my current vision, choosing
         | not to get a prescription. Luckily I figured out that it was
         | blue light that was bothering me and once I turned it down I
         | haven't had any problems since. I'm in my mid 40s and my vision
         | has naturally deteriorated a bit but I am still fine with no
         | prescriptions.
         | 
         | And I don't believe this to be placebo. Every time I stare at a
         | regular screen for longer than 5 minutes I get eye strain. At
         | the same time I suspect this doesn't help everyone, but at
         | least to me this is a great solution that still works.
        
           | cellularmitosis wrote:
           | Can you elaborate on "no way back"?
        
             | denkmoon wrote:
             | Not OP, but when I got glasses as an adult and while they
             | really improved the sharpness of my vision I could feel my
             | unassisted vision getting worse, so I stopped using them
             | and get by with slightly unfocused but unassisted vision. I
             | assume if I wore them full time my unassisted vision would
             | degrade to the point where I then need the glasses full
             | time.
        
               | ifwinterco wrote:
               | I've got half a diopter (ish) of astigmatism in my right
               | eye and it can be slightly annoying but interesting to
               | know that using glasses would risk making it worse.
               | 
               | The weird thing is it seems to get noticeably worse or
               | better depending on how much time I spend outside
        
               | pseudalopex wrote:
               | Your assumption was false.[1]
               | 
               | [1] https://health.clevelandclinic.org/do-glasses-make-
               | your-eyes...
        
               | maccard wrote:
               | I got glasses 2 years ago for a very minor prescription.
               | Your eyesight sucked before you've just forgotten how
               | badly. I had an eye test very recently for Contacts and
               | my prescription is the same 2 years later
        
             | tartoran wrote:
             | I meant that once you decide to wear prescription optics
             | you can't go back to not wearing them, of course excluding
             | eye surgery. In my case I could stick to good enough vision
             | and luckily 20 years later Im still not wearing glasses. My
             | main point was that I was getting eye strain from blue
             | light and once I reduced it the problem dissapeared.
        
               | nsxwolf wrote:
               | This isn't true? Myopia develops rapidly in youth then
               | stabilizes in adulthood. It gets a worse with age, not
               | corrective lenses. Then sometime after 40 you flip to
               | presbyopia when your lenses lose flexibility.
        
               | tartoran wrote:
               | I don't have severe myopia and I'm fine with no glasses
               | for now. The optometrist detected .5 correction needed
               | but advised me to not go for it for the reason I
               | mentioned. I think they are more qualified to give this
               | advice than some rando on the internet. If they were a
               | mercenary they'd tell me to go for it, that optometry
               | practice was part of an eye glasses store and I'm sure
               | they'd gain from my business there. And here I am 20
               | years later not wearing glasses yet. As I'm getting older
               | my vision is getting slightly worse, I'll probably get to
               | wear them at some point but that's beside the point.
        
         | amelius wrote:
         | Are you sure you are not also changing total luminance?
        
         | himata4113 wrote:
         | I actually cannot use my monitor without nightshift, any white
         | page just makes my eyes water, painful even. I had it off for a
         | day when I switched to linux and immediately my eyes started
         | drying out.
         | 
         | Safe to say it works for making your eyes less tired at least.
        
         | nsxwolf wrote:
         | I love Night Shift.
        
         | taeric wrote:
         | I find it somewhat pleasant, but by far the best thing I did to
         | help my eye strain was greatly lower the brightness. Basically,
         | I was told to make it so that my phone's camera could see
         | something on the screen and my desk at the same time without
         | washing out.
         | 
         | After doing that, I have found that the "temperature" of the
         | screen doesn't really matter to me that heavily.
        
           | kpw94 wrote:
           | > Basically, I was told to make it so that my phone's camera
           | could see something on the screen and my desk at the same
           | time without washing out
           | 
           | +1. The low-tech version of this I've heard and I've been
           | doing is:
           | 
           | Hold a printed white paper sheet right next to your monitor,
           | and adjust the amount of brightness in monitor so the monitor
           | matches that sheet.
           | 
           | This of course requires good overall room lightning where the
           | printed paper would be pleasant to read in first place,
           | whether it's daytime or evening/night
        
             | taeric wrote:
             | I think this was what I was told the first time. The
             | advantage of taking a picture with my phone's camera is it
             | kind of made it obvious just how much brighter the screen
             | was then the paper.
             | 
             | Which, fair that it may be obvious to others to just scan
             | their eyes from screen to paper. I've been surprised with
             | how much people will just accept the time their eyes have
             | to adjust to a super bright screen. Almost like it doesn't
             | register with them.
        
         | metalliqaz wrote:
         | My Windows 10 PC glitches out most days where the 3rd monitor
         | doesn't properly apply the Night Light setting. So I turn it
         | off and on to fix it. The full blue brightness is awful and
         | definitely harsh on my nighttime eyes. I'm not sure I could
         | believe it's placebo
        
       | pier25 wrote:
       | > _I took a sample of 4 websites /apps (Google, X, Github, and
       | VSCode) with the SpyderX colorimeter + a diffuser to average over
       | a larger area of the screen, and found reductions in luminance
       | ranging from 92% to 98%! That's huge._
       | 
       | What about TikTok or Youtube?
        
       | SoftTalker wrote:
       | I have my phone in monochrome (i.e. greyscale) mode and just
       | subjectively it's much easier to look at especially at night. I
       | have it at the lowest brightness and it's still very readable.
       | Human eyesight is basically monochrome in low light settings
       | anyway.
        
       | cjbgkagh wrote:
       | I use blue blocking glasses, like Bono but darker and they do
       | work. I also use UV LEDs to help me wake up, which also works.
       | 
       | I agree with the premise that night shift and other color warmth
       | features are insufficient to have a strong effect, though they do
       | help with eye strain which is still a positive.
        
       | harrall wrote:
       | I firmly believe this varies between people significantly.
       | 
       | Blue light filters do not work for me because I fall asleep on
       | command everyday all the time regardless if WW3 is outside.
       | 
       | BUT it also seems the effect of poor sleep seems to be MUCH worse
       | for me than other people. I go from extreme motor coordination to
       | dropping cups in a span of 3 days of poor sleep.
       | 
       | There's a chemical called adenosine which accumulates over the
       | day that induces sleepiness and there are genetic variations that
       | can affect your susceptibility to it. Receptors notice the
       | accumulation of adenosine and use it as a signal to "scale down."
       | 
       | I think that I am more sensitive, explaining my ease of sleep but
       | also the effect of it when it accumulates due to poor sleep
       | (sleep flushes it away). Yeah it's great when I'm in bed but it's
       | not great when I want to throw a ball and my brain wants to be
       | stingy. It basically means that someone else's "helpful guide to
       | sleep" is completely different from my "helpful guide to sleep."
        
         | lowdest wrote:
         | >the effect of poor sleep seems to be MUCH worse for me than
         | other people. I go from extreme motor coordination to dropping
         | cups in a span of 3 days of poor sleep.
         | 
         | Are you sleeping enough? When I was getting too little sleep,
         | averaging 5.5 hours per night, this described me well. A single
         | sleep interruption could make me lose most of a day of work.
         | I'm sleeping better and longer now, and it seems I'm more able
         | to tolerate small interruptions.
        
           | harrall wrote:
           | Yeah I've gotten 8 hours of sleep almost everyday for 15
           | years, ever since I put 2+2 together. In my early 20s, I
           | didn't like being bad at sports and I found sleep was my
           | single most important factor.
           | 
           | Similar to you, I also noticed that if I miss good sleep for
           | several days, it stacks. I treat sleep like a battery. A day
           | uses up 20% and good sleep fills it back up, but only like
           | 30%. One missed night isn't that bad but I also can't recover
           | several nights' worth.
        
       | mikkupikku wrote:
       | Why is it that a few people seem to get bent out of shape by
       | redshift and/or dark modes? If you don't like it, don't use it.
       | Whining about scientific evidence is pointless, even if it all
       | only comes down to user preferences with no science behind it, so
       | what? Let people enjoy things.
        
       | ctbeiser wrote:
       | It seems pretty clear in the OP that headline is misleading--they
       | do work, just not as well as he would like. I think that a 50%
       | cut in light emission is pretty good--and you can stack that with
       | the other interventions listed, like auto-dark mode and reducing
       | light in your room.
        
         | leni536 wrote:
         | Note that it's only 50% if you don't normalise back to absolute
         | brightness.
        
       | nicoburns wrote:
       | Blue light filters definitely work for me. But it needs to be a
       | strong filter (quite a bit stronger than the strongest setting of
       | Apple's built-in filter).
        
         | nomel wrote:
         | Yes, article title is clickbait. Partial filters don't work,
         | but as they suggest, 100% filter of blue light (resulting in no
         | blue light present), DO work.
         | 
         | You can get this with Apple's strongest filter, the color
         | filter, in Settings > Accessibility > Display & Text Size >
         | Color Filters, rather than night shift. Only red sub-pixels are
         | illuminated with it. It can be added to the triple click power
         | button accessibility shortcut.
         | 
         | That's what I use. I have a shortcut set to enable it when I
         | put my AirPods in at night.
        
       | Groxx wrote:
       | So the main claim presented here is that _reducing blue_ reduces
       | total  "light" (lumens? watts?) by 50% (totally believable), and
       | that reduction in light is all that matters for sleep?
       | 
       | That seems reasonable. The pseudoscience wankery that the fad has
       | brought bothers me a lot too.
       | 
       | ... but I'm not sure that's much of an argument against blue
       | light filters, aside from color complaints. That seems to
       | _support_ that it 's Useful and Good and is Achieving Its
       | Intended Goal. It's reducing total luminance, _because people
       | prefer it over reducing screen brightness overall_. I sure as
       | heck do anyway (as night shift modes, they 're a more
       | comprehensive option than dark mode), though I think I'll
       | experiment with just reducing brightness a bit.
       | 
       | ----
       | 
       | For melatonin in particular, fully agreed. The recent trend of
       | "can't even get <5mg in stores, and >10mg is appearing regularly"
       | in the USA is mind-boggling to me. AFAICT it's exclusively
       | because it's a "supplement" and therefore practically
       | unregulated, and these companies don't give a shit about anyone
       | they harm, just profit.
       | 
       | Start with something like https://a.co/d/0dISg7oa (0.3mg, this is
       | what I personally use) and go up from there, slowly.
        
         | SoftTalker wrote:
         | So buy 5mg, and split the tablet in half.
        
           | Groxx wrote:
           | that'd give you 2.5mg, which is still _almost 10x more_ than
           | what I linked.
           | 
           | it's possible to split and separate them enough of course,
           | but beyond "roughly half" it gets rather difficult. I've
           | considered getting the liquid ones and a micro-dropper for
           | smaller doses (if they'd even be small enough, many
           | combinations are not), but 0.3mg pills are rather convenient
           | and worth the small amount of money for me.
        
             | SoftTalker wrote:
             | Oops, missed the decimal position!
        
             | IAmBroom wrote:
             | Some research indicates people over 50 (includes me)
             | achieve best results at 0.3 microgram dosage, which is
             | 1,000 lower(!). Higher dosages reduce the effect.
             | 
             | You might take a quick sec to look into the data. You can
             | buy 5mcg on Amazon, although 5 mg is more common (and 10mg,
             | and ...).
        
               | Groxx wrote:
               | after an initial "... is that a misquote too? sounds
               | super low" I decided to hunt around. I haven't seen
               | anything on _that_ low of a dose... but doing the math,
               | it does seem to make some sense I suppose. a rough check
               | of the total amount of melatonin in your blood at night
               | implies something like 0.5mcg at peak (peak concentration
               | at ~100pg /ml times 5L of blood). lots more is produced
               | in a night because it has a short half-life, but yea,
               | blood concentration is lower than I remembered.
               | 
               | what I _also_ haven 't seen though is anything covering
               | how well it's absorbed through your digestive system.
               | 0.3mcg intravenously I can certainly see being effective,
               | but orally? sublingually? not sure. but you've definitely
               | got me interested in looking more :)
               | 
               | (initial results: https://en.wikipedia.org/wiki/Melatonin
               | _as_a_medication_and_... implies it varies quite a lot,
               | but I'm seeing it centering around 15%-ish many places.
               | so you might want like 3mcg to hit normal levels? and
               | https://pmc.ncbi.nlm.nih.gov/articles/PMC5405617/ is
               | implying 1-5mg -> 10x-100x normal concentration peak, so
               | that does hit the right ballpark reasonably well... I
               | guess I'm going to start experimenting with even smaller
               | doses!)
        
         | gowld wrote:
         | No, in the OP (after an unclear intro that confuseed many
         | readers), there is a graph that shows blue wavelength intensity
         | is important, but software light filters don't filter a lot of
         | it, and the effect is cancelled by increasing overall
         | brightness.
        
           | Groxx wrote:
           | If software filters are reducing _total_ light by 50% while
           | only affecting blue-ish tones, and that 's a total light
           | level comparable to _multiple_ brightness steps on a Mac...
           | tbh I think it 's reducing it quite a lot. Many I see using
           | them (myself included) don't tweak brightness when enabling
           | it, and many (all?) systems don't adjust their brightness to
           | match the perceived change from a software filter (on my
           | Linux machines in particular I have never seen this happen,
           | don't know about Macs though).
           | 
           | Half is not a lot, sure, but their ultimate suggestion is to
           | do the same ~half change:
           | 
           | > _You can decrease the amount of light coming from your
           | screen by more than half simply by dimming the screen by
           | several notches._
           | 
           | which is definitely significantly more than I see people
           | doing voluntarily in the hundreds of millions.
           | 
           | Do they have any evidence that people are raising system
           | brightness to match the 50% loss from the filter? If not, it
           | still seems like a rather significant mark in their favor.
           | Perhaps not _sufficient_ to meet the goals (they seem to be
           | recommending a larger change, but aren 't specific), but I
           | see no claim that a lesser decrease in light is _worse_.
           | 
           | ---
           | 
           | Late edit: on second thought... let's go through this more
           | rigorously. For both myself and any other readers, because I
           | want to make sure I'm following it accurately too.
           | 
           | The main explicit points in this article are, in order:
           | 
           | - night shift does not help with sleep (the main claim)
           | 
           | - blue light is not special, in particular because the
           | "[most] sensitive to blue" research is mis-quoted to mean
           | "blue is bad", but it's actually sensitive to blue and green
           | (seems very well supported)
           | 
           | - night shift reduces blue and green by about half (tested
           | themselves)
           | 
           | - half of absolute is not a lot because vision and a lot of
           | the related biology is logarithmic (100% agreed)
           | 
           | - halving light affects 25%-50% of melatonin levels (linked
           | research)
           | 
           | - many people use Night Shift (100% agreed, and they have
           | decent data to back it up)
           | 
           | - dark mode is better than night shift (>90% vs ~50%, implied
           | leaning on the linked research earlier. agreed, seems
           | straightforward)
           | 
           | - dimming your screen by several steps is the same or better
           | than night shift (as it decreases brightness more, same
           | reasoning as dark mode. agreed.)
           | 
           | That still sounds rather in favor of Night Shift. It's
           | targeting the correct color range (NOT the pseudoscience
           | blathering of just blue blue blue), it has a moderate affect
           | on melatonin levels at the light level changes it creates,
           | and it's used by a huge amount of the population.
           | 
           | Nowhere in there that I can see is anything to back up "Night
           | Shift does not work". Only "it seems to be doing things
           | right, it just isn't quite enough on its own" and "ARGH it's
           | not just blue light STOP PROMOTING FAD PSEUDOSCIENCE". That
           | seems... fine? Most things are not silver bullets.
        
       | ltbarcly3 wrote:
       | Well they work in that the color temperature of the light in my
       | house is much cooler during the day than at night, and it's nice
       | to match it so it doesn't look jarring.
        
       | pclowes wrote:
       | You can just do things. Not everything needs a study, you don't
       | have to justify yourself to anyone!
       | 
       | Try things, if you like them, do them!
       | 
       | Try not living a neurotic "study" based life, I am trying it and
       | its pretty great!
        
         | Barbing wrote:
         | (just nothing from Goop)
        
         | tartoran wrote:
         | Absolutely and this is something that can be tested rather
         | easily. If blue filters aren't immediately helpful to eye
         | strain then they probably don't work for you but if they are
         | they probably do work for you.
        
           | IAmBroom wrote:
           | You can test the negative easily, but the positive is harder.
           | Thus: placebos.
        
             | tartoran wrote:
             | You're saying that my eyes straining going away from
             | reduced blue light is placebo? I can feel it right away and
             | it gets worse in minutes, time and time again. As soon as I
             | remove blue light the strain is gone. Honestly, I don't
             | care what other people have to say, to me it's obvious that
             | it helps and I stick to it. Again, I don't think this is
             | universal and it may not help you if you don't notice
             | immediate improvement.
        
         | IAmBroom wrote:
         | I am aware that meta-studies of glucosamine chondroitin show No
         | Significant Gains in joint pain. I would never waste my money
         | on it.
         | 
         | But my newly adopted dog had hip issues, and I bought a few
         | months worth of a diet supplement in the hopes of doing
         | something meaningf... dammit, it's glucosamine.
         | 
         | They claimed double-blind studies showed decreases in limping
         | in just two months.
         | 
         | Two months, more or less, I stopped seeing him limp by the time
         | we left the dog park. He still does sometimes, but it's rare -
         | not every damn day, by any means.
         | 
         | We aren't that fricking different biologically from dogs in our
         | skeletal attachment system. Maybe it's still a placebo, but it
         | seems to defeat that idea. Maybe enough human issues are based
         | on things that don't translate to dogs - sitting at a desk all
         | day, eating junk food, walking upright... - that it helps them,
         | but not enough of us.
         | 
         | Don't know. These GC supplements have convinced me it's worth
         | my money, and he loves eating them, so he votes 'yes', too.
        
           | rkomorn wrote:
           | I found it interesting that placebo effect is also sort of
           | relevant in pet care: it makes owners believe the pet is
           | doing better.
           | 
           | Unfortunately, the study that showed this used the same
           | medicine my dog had been on, and since it was for epilepsy, I
           | can totally believe that whether I thought it worked had no
           | connection to its effectiveness.
        
       | pie_flavor wrote:
       | If you aren't aware, your phone's screen can go much dimmer than
       | the minimum brightness offered by the slider, if it supports HDR.
       | There are apps that use an HDR screen overlay to lower brightness
       | all the way down to the dimmest you can perceive. In my own
       | experience, 'half' the brightness of 'minimum' brightness is
       | plenty dark enough to not disturb sleeping at all if using my
       | phone in bed.
        
         | Barbing wrote:
         | Also for third-party monitors with MacBooks: BetterDisplay
         | 
         | Can even use an external keyboard's native brightness buttons.
         | Can still use f.lux if desired too though Night Shift maybe
         | Sherlocked there a bit...
        
       | lisper wrote:
       | Night shift seems to have a very strong causal effect on my sleep
       | cycles. Up until about ten years ago I was a night owl, rarely
       | falling asleep before midnight and rarely waking up before 8.
       | Then I started getting serious about light hygiene and using
       | night shift and now I'm a serious day person, rarely staying
       | awake after 11 and rarely waking up after 7. But the real
       | clincher is that when I travel I don't change the time zone on my
       | computer (because it screws up my calendar). But my sleep cycle
       | continues to track my home time zone for a very long time. I life
       | in California, but at the moment I'm in Hawaii. I've been here
       | three weeks so far. At home I'd fall asleep around 11 and wake up
       | around 7, but here I'm getting sleepy at 9 and waking up at 5.
       | 
       | My wife, on the other hand, is a hard-core night owl even with
       | night shift. So apparently there is a lot of individual
       | variation.
       | 
       | This article has inspired me to do a control experiment by
       | switching night shift off. Check back here in a week or so for
       | the results.
        
         | Barbing wrote:
         | >inspired me to do a control experiment
         | 
         | Delightful, see ya the 27th!
        
         | gowld wrote:
         | > Night shift seems to have a very strong causal effect on my
         | sleep cycles.
         | 
         | > light hygiene and using night shift
         | 
         | The OP article is primarily about separating the variables you
         | lumped together.
        
       | crazygringo wrote:
       | These are the kinds of articles that give science a bad name, and
       | that make people anti-science.
       | 
       | You might as well try to claim hot tea doesn't help you get to
       | sleep, or reading before bed doesn't, or whatever else you do to
       | wind down.
       | 
       | I personally don't care if some narrow hypothesis about blue
       | light and melanopsin is false. I know that low, warm, amber-
       | tinted light in the evening slows me down in a way that low,
       | cold, blue-tinted light does not. That's why I use different,
       | warmer lamps at night with dimmers, and keep my devices on Night
       | Shift _and_ lower brightness. It works for me, and seems to mimic
       | the lighting conditions we evolved with -- strong blue light
       | around noon, weaker warmer light at sunset, weakest warmest light
       | from the fire until we go to sleep. Maybe it doesn 't work for
       | everybody. That's fine. But it certainly does for me.
       | 
       | And maybe it's not modulated by melanopsin. Or maybe it's not
       | about blue light, but rather the overall correlated color
       | temperature (CCT), e.g. 2100K instead of 5700K. Who knows.
       | 
       | But this type of article is bad science writing. It shows why
       | _one hypothesis_ as to why a warmer color temperature would
       | result in _one other physiological change_ isn 't supported. That
       | doesn't mean "blue light filters don't work" as a universal
       | statement. It's hubris on the part of the author to assume that
       | this _one_ hypothesis is the _only potential mechanism_ by which
       | warmer light might help with sleep.
       | 
       | And it's this kind of science writing that turns people off to
       | science. I know, through lots of trial and error and
       | experimentation, that warm light helps me fall asleep. And here
       | comes some "AI researcher and neurotechnologist" trying to tell
       | me I'm wrong? He says it's "aggravating" that people are
       | "actually using Night Shift". I say it's aggravating when people
       | like him make the elemental mistake that showing _one_ biological
       | mechanism doesn 't have an effect, means _no other_ mechanisms
       | can either.
        
         | AshamedCaptain wrote:
         | > These are the kinds of articles that give science a bad name,
         | and that make people anti-science.
         | 
         | No, it is attitude like yours that brings humanity a bad name.
         | 
         | "Blue light effects" have always had highly questionable
         | evidence behind it, what has been sold and marketed under the
         | guise of it has had _zero_ evidence behind it. But now that you
         | are reminded that it is actually bullshit, you react with
         | skepticism.
         | 
         | "Feels good to me" is hardly evidence to begin with. It's
         | something that is even more flimsy than sociology. I have my
         | doubts it should even be called medicine.
         | 
         | You have to remember that a shitton of people day after day
         | "show" "evidence" that homeopathy works. Even though it has no
         | plausible mechanism of action. So clear mechanism of action is
         | about as important as the evidence itself. (see Science-based
         | medicine)
         | 
         | I could understand (not justify) skepticism in many cases (such
         | as "common wisdom" from 1000 years ago) but this particular
         | topic should have raised your skepticism 20 years ago back when
         | the craze/marketing stunt was starting, and not now.
        
           | chuckadams wrote:
           | Someone says that other psychological factors (which have
           | physical effects) help them sleep and they "bring humanity a
           | bad name"?
           | 
           | Maybe think on that a little bit.
        
             | AshamedCaptain wrote:
             | No, he said "this gives science a bad name"/"makes people
             | anti-science" because some article published something that
             | contradicts his anecdote of how well he thinks he sleeps.
             | That gives humanity a bad name. And your direct insults do,
             | too (which fortunately have been edited out).
        
               | chuckadams wrote:
               | The direct insult where I said "touch some fucking
               | grass"?
               | 
               | I certainly stand by it now.
        
               | IAmBroom wrote:
               | Why? You're proud of your insults?
        
           | crazygringo wrote:
           | > _" Feels good to me" is hardly evidence to begin with_
           | 
           | Where did I say anything like that? Please don't
           | mischaracterize my comment, that's not helpful. It's not that
           | it "feels good", it's that it helps at least some people fall
           | asleep more easily, and I know this from personal experience.
           | And many, many other people have written that it does the
           | same for them.
           | 
           | > _" Blue light effects" have always had highly questionable
           | evidence behind it... But now that you are reminded that it
           | is actually bullshit_
           | 
           | You're right that the evidence _for_ it is questionable. But
           | you know what else there 's no conclusive evidence for? That
           | hot herbal tea helps you fall asleep. Or soothing music. Or
           | bedtime stories. Because the funding usually isn't there to
           | perform the kind of large-scale studies required to establish
           | these things, because it's just not a priority or even a good
           | use of our dollars. And lack of evidence for, is not the same
           | as evidence against.
           | 
           | My point is, nothing in this article _does_ establish that it
           | is  "actually bullshit". That's a _gross_ misreading of the
           | science, and that 's what I'm criticizing the article over.
           | 
           | People experiment with things and discover what works and
           | what doesn't. Again, nobody's going around complaining that
           | there's no scientific evidence lullabyes don't help put you
           | to sleep. And neither lullabyes, nor turning your lights down
           | to amber, have anything to do with homeopathy. You can't
           | possibly suggest they're doing _harm_. People aren 't using
           | amber lighting at night _instead of getting their cancer
           | treated_.
           | 
           | But for some reason, low amber lighting to help with sleep
           | makes you and the article author upset? Why? Why does that
           | make you upset, but not hot tea or lullabyes? Or do those
           | make you upset too?
        
             | AshamedCaptain wrote:
             | "feels good to me" and "helps me sleep more easily" are
             | about the same thing: flimsy and almost non-quantifiable
             | personal experiences. About the same level with "I dream of
             | nicer things".
             | 
             | > And many, many other people have written that it does the
             | same for them.
             | 
             | So people write for homeopathy. Homepathy actually is the
             | precursor for using this type of "evidence" for development
             | and study of new "drugs" (hint: this evidence ends up going
             | nowhere useful, quickly).
             | 
             | > Or soothing music. Or bedtime stories. Because the
             | funding usually isn't there to perform the kind of large-
             | scale studies required to establish these things, because
             | it's just not a priority or even a good use of our dollars.
             | 
             | Oh, there is. There are way more studies about this than
             | you can possibly think of. There are medical journals
             | reporting clinical experiences about this daily. You are
             | saying this on an article about study about one of these,
             | ironically enough.
             | 
             | > And lack of evidence for, is not the same as evidence
             | against.
             | 
             | https://en.wikipedia.org/wiki/Russell%27s_teapot
             | 
             | > My point is, nothing in this article does establish that
             | it is "actually bullshit".
             | 
             | Why not?
             | 
             | > But for some reason, low amber lighting to help with
             | sleep makes you and the article author upset? Why? Why does
             | that make you upset, but not hot tea or lullabyes? Or do
             | those make you upset too?
             | 
             | You are the one who suddenly claims this makes people
             | "anti-science", when this particular bullshit is not even
             | 20 years old, and it was already known to be suspect 20
             | years ago. It is just ridiculous that it is now suddenly
             | such a core belief of your persona that even being reminded
             | that it is most likely bullshit is going to drive you to
             | reject science outright.
             | 
             | As I said, I could at least _understand_ (but not justify)
             | much older claims, such as ancient chinese practices or
             | whatever. This makes they make me upset indeed (this is
             | pseudoscience, after all), but what makes me even more
             | upset is the creation of new pseudo-scientific or even
             | anti-scientific "popular wisdom" _in this age_.
        
               | crazygringo wrote:
               | I think you have not actually understood what I wrote,
               | because of this part:
               | 
               | >> _My point is, nothing in this article does establish
               | that it is "actually bullshit"._
               | 
               | > _Why not?_
               | 
               | I've already said it multiple times. Allow me to repeat
               | myself:
               | 
               | > _make the elemental mistake that showing one biological
               | mechanism doesn 't have an effect, means no other
               | mechanisms can either._
               | 
               | You've written a lot, but you haven't understood that
               | this is the core mistake of the article, and the core
               | mistake of what you're trying to argue.
               | 
               | You reply with a reference to Russell's teapot, and that
               | would be fine if you were merely trying to make the point
               | that the effect of amber light on sleep has not been
               | sufficiently proven. But _you 're_ the one literally
               | calling it "bullshit", i.e. _dis_ proven. That's wrong.
               | There's no high-quality study conclusively demonstrating
               | it _doesn 't_ have an effect.
        
               | AshamedCaptain wrote:
               | Certainly you can claim that because not all mechanisms
               | have been disproven yet, then there could still be an
               | effect. That is why I quote Russell's teapot. Your claims
               | are technically not disproven, and may not even be
               | possible to disprove, but that doesn't mean that the
               | existence of the teapot is (most definitely) bullshit.
               | This is what the example of Russell's teapot is trying to
               | show.
               | 
               | I also keep continuously putting the example of
               | homeopathy because it is exactly the same. Homeopathy has
               | plenty of (weak) evidence, but no known mechanism of
               | action. All the proposed religious, memory of water, etc.
               | have been disproved. Certainly you can argue that
               | homeopathy could still be a thing because there could be
               | some physical/biological mechanism that has not yet been
               | disproved! But this is just nitpicking: homeopathy is
               | still bullshit. In the same way that a teapot in space is
               | bullshit.
               | 
               | Anything else is a (useless) nitpick.
               | 
               | In any case, even from day #1 it's been known that blue
               | light could possibly have a mechanism, but there's always
               | been a big stretch from there to claiming that blue light
               | filters/night shift have an effect, and the evidence for
               | the latter is substantially lacking.
               | https://sciencebasedmedicine.org/blue-light/
        
               | crazygringo wrote:
               | I'm sorry, but using the idea of Russell's teapot to
               | claim anything without rock-solid proof is "bullshit" is
               | a deep misunderstanding of the idea. It's wrong, it's
               | offensive, and it's not helpful to genuine understanding.
               | 
               | Amber light is not Russell's teapot. There's widespread
               | anecdotal reporting that it helps with sleep. It's not
               | something nonsensical like a teapot between Earth and
               | Mars. And for you to suggest that they're the equivalent
               | is, frankly, arguing in bad faith.
               | 
               | The world of knowledge is not divided, black-and-white,
               | between things that are scientifically proven and
               | "bullshit". Probably the vast majority of practical facts
               | we rely on daily are not "proven" with empirical studies.
               | That doesn't make them "bullshit". I hope you can
               | understand that.
        
               | AshamedCaptain wrote:
               | No, I do not understand why I cannot call homeopathy
               | bullshit. There's plenty of widespread positive anecdote
               | for it, too!
               | 
               | Why would you think calling one bullshit is "offensive"
               | and not the other? You realize that this "gray" scale
               | that you claim is as unscientific as it gets, right?
               | After all, it worked for me! And I hear that it works for
               | my friends! How can homeopathy/blue light
               | filters/whatever-ritual-you-like-today not work? How can
               | there not be a teapot on the sky?
               | 
               | If the problem is with the word "bullshit", call it
               | pseudo-scientific, but it is almost the same thing.
               | 
               | Tomorrow there could be some evidence of an effect shown
               | in the opposite direction (e.g. blue light filters
               | _harming_ sleep quality*, or performance the day after,
               | or whatever) and you would be as skeptical as with claims
               | of no effect, if not more. See the recent article of
               | white noise in HN and how it was met in the comments.
               | 
               | * Because of people (or worse, software) turning their
               | screens' brightness up to compensate, which I already
               | read an article about long time ago...
        
         | anonymars wrote:
         | > But this type of article is bad science writing. It shows why
         | one hypothesis as to why a warmer color temperature would
         | result in one other physiological change isn't supported
         | 
         | I don't know if I'd even give them that credit (emphasis mine):
         | 
         | > Halving the luminance, at best (around 20 lux baseline)
         | _might get you from 50% to 25% melatonin suppression._
        
         | orbital-decay wrote:
         | What if these filters also cure cancer by some mechanism that
         | isn't known yet? Who knows, it might be true!
         | 
         | The entire _medical_ usage of blue light filters hinges on just
         | a few papers. If you really can prove those studies
         | inapplicable you can prove that there 's no objective reason to
         | use them (I'm not necessarily saying the author did that).
         | 
         | Whether these filters feel nice is entirely unrelated question,
         | nobody stops you from decorating your living space as you see
         | fit.
        
       | wa008 wrote:
       | Based on my experience, most health benefits are from personal
       | habits over external hardware. But people care health so much,
       | it's a great opportunity for merchants to get revenue.
        
       | alejohausner wrote:
       | I bought some amber glasses from blublocker.com[1], because they
       | link to a research paper that actually measured how much of each
       | wavelength their filters allow (as well as other brands). They're
       | pretty dark, so you have to crank up the brightness on your
       | screen, but I'm confident that I'm not getting ANY blue.
       | 
       | 1: https://www.blublocker.com/blogs/news/what-blue-light-
       | blocki...
        
         | kb9alpp wrote:
         | Nice. The article also mentions BluTech lenses (BluTech LLC,
         | Alpharetta, GA). I've found the marginal utility of bluelight
         | blocking solutions are very context specific, indeed. And
         | mostly-completely bahokie garbage, sadly, but not when it's
         | BluTech and BluBlocker. BluTech/BluBlocker for the screen-
         | induced fatigue is the correct solution. I always get BluTech
         | HI Indoor AR pucks for my prescription lenses. And just switch
         | to prescription sunglasses when I go outside.
        
       | cptskippy wrote:
       | I have Night Light perpetually on with all of my devices because
       | I find it softens everything and makes viewing displays less
       | harsh, less garish, less vivid, and less intense. I don't need
       | eye searing HDR constantly cooking my retinas.
        
       | yathern wrote:
       | > Unless your strategy is to create a photo-lab-like screen in
       | pure black and red, or wear deep-red-tinted glasses, it's
       | unlikely that a pure colorshift strategy will cut out that big of
       | a chunk of the spectrum.
       | 
       | I absolutely think this is the right approach. The glasses which
       | do 'blue light filtering' which barely change your perception are
       | clearly placebo, but a very strong redshift I think is obviously
       | a different creature.
        
         | EA-3167 wrote:
         | Absolutely, although dark orange seems to work well enough. If
         | you can put them on and still tell the difference between most
         | colors, they aren't working. I use my pair for one purpose:
         | reading in bed with a backlit e-reader. I can't imagine trying
         | to do much else with them on, they have plastic wings to block
         | light from the side and they're not light.
         | 
         | But they work.
        
         | hinkley wrote:
         | I have a red flashlight I use at night to read books. It's
         | weird after an hour I don't really see it as red anymore, just
         | dim off white.
        
       | zcw100 wrote:
       | I replaced all the light switches in my house with smart dimmers
       | and have the lights dim in the evening. It happens in steps so
       | it's noticeable and it's like a clock ticking down. I don't know
       | if there's anything scientific about it but it's pleasant, like
       | the house is going to sleep so maybe I should too.
        
       | TACIXAT wrote:
       | I have had success with an extremely aggressive red filter. My
       | unchecked sleep schedule has me going to bed around 4 am,
       | consistent over decades. I don't consume caffeine or any other
       | stimulant. In the last 4 months I switched my lights to LED bulbs
       | to turn red at 6pm and use QRedshift on Linux (Mint) with the
       | temperature set to 1000k at 6pm. I have consistently been falling
       | asleep around midnight. What is remarkable to me is that I am
       | actually feeling tired at night.
        
       | jrm4 wrote:
       | It's funny, I'm _so comfortable_ calling this guy an idiot purely
       | based on the fact that I 've taken up Bob Ross style painting in
       | like the last 2 years.
       | 
       | Teaches you to pay attention to "objective" colors. And at night,
       | guess what, the colors get more red and less blue. I don't have
       | to pull out as much blue paint for the night scenes.
       | 
       | It would be utterly naive to not thing that there's -- perhaps
       | purely "psychological" (not sure if that's the exact concept but
       | hey) effect by making the "white" on your screen, look like like
       | the "white" you will definitely see in real life, which is going
       | to be orange-r.
        
       | iainctduncan wrote:
       | Regardless of the sleep effect (or lack of) they absolutely do
       | work for reducing eye strain for migraineurs.
       | 
       | It's noticeable to me all the time, but if I'm borderline
       | migraining, or recovering from a migraine, the difference between
       | shifted and not is something I can feel instantly. Shifting all
       | the way over enables me to eek out some work after a migraine
       | without it flaring back up again.
        
       | Waterluvian wrote:
       | I really don't care if they "work" or not. I find it incredibly
       | cozy to have a warmer, calmer screen in the evening.
        
       | reenorap wrote:
       | The entire blue light madness is based on a poor study where N
       | was around 8. And the difference in sleep was something like 15
       | mins. The entire study was based on crap but somehow the entire
       | world has run rampant on the idea that blue light has this
       | profound effect. It just goes to show that bad science is easily
       | propagated, even when there's even more sources of information.
        
       | baud9600 wrote:
       | I added the "Noir" extension to mobile Safari, now I
       | automatically get dark mode on all websites including Hacker
       | News.
        
         | hinkley wrote:
         | I'm surprised by how may don't have a dark mode though. I
         | decided to do it for my blog despite not really using it
         | myself, and ended up sticking with it on. Still getting blasted
         | in the face by eggshell white everywhere I click.
        
       | james_marks wrote:
       | I have a triple-click shortcut in iOS to use the accessibility
       | features to go below the min dim settings.
       | 
       | Otherwise even dark mode is way too bright in a dark room.
        
       ___________________________________________________________________
       (page generated 2026-02-20 23:00 UTC)