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Blue light filters don't work – controlling total luminance is a better bet

234 points by pminimax 7mo ago

snet0 7mo ago
But have you considered that it feels better?
- stronglikedan 7mo ago
  so do placebos
  - kurthr 7mo ago
    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 7mo ago
    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 7mo ago
      Placebo and “manifesting”—the latter sounds mockable but pretty much the same thing, harmless if helpful so hey!
      - nickthegreek 7mo ago
        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 7mo ago
        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 7mo ago
    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 7mo ago
    and? placebo is often effective.
debo_ 7mo ago
> 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.
- nine_k 7mo ago
  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.
- loloquwowndueo 7mo ago
  What did you do to tackle your insomnia?
  - smt88 7mo ago
    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_ 7mo ago
      That was my experience as well.
  - m3047 7mo ago
    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.
koalacola 7mo ago
Is this your article OP?
aethrum 7mo ago
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?
- smohare 7mo ago
  [dead]
- thenewnewguy 7mo ago
  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 7mo ago
    >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 7mo ago
      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.
socalgal2 7mo ago
[flagged]
pier25 7mo ago
> 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 7mo ago
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.
- culi 7mo ago
  I have an accessibility shortcut to turn my screen greyscale with triple taps but I kept turning it off so I could see the clues on sudoku and now I've forgotten I even had this for almost a year Low brightness is great though. I didn't realize most of the battery drain on a phone is often just the screen. Lowering the brightness to as little as I need has been great for battery life
cjbgkagh 7mo ago
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 7mo ago
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 7mo ago
  >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 7mo ago
    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 7mo ago
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.
- IAmBroom 7mo ago
  Yes! Leave me and my mercuric-laudanum tooth-straightening sales alone! People like the taste!
ctbeiser 7mo ago
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 7mo ago
  Note that it's only 50% if you don't normalise back to absolute brightness.
nicoburns 7mo ago
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 7mo ago
  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 7mo ago
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 https://a.co/d/0dISg7oa (0.3mg, this is what I personally use) and go up from there, slowly.
- SoftTalker 7mo ago
  So buy 5mg, and split the tablet in half.
  - Groxx 7mo ago
    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 7mo ago
      Oops, missed the decimal position!
    - IAmBroom 7mo ago
      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 ...).
ltbarcly3 7mo ago
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 7mo ago
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 7mo ago
  (just nothing from Goop)
- tartoran 7mo ago
  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 7mo ago
    You can test the negative easily, but the positive is harder. Thus: placebos.
    - tartoran 7mo ago
      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 7mo ago
        That's reasonable: it works for you. But be aware that, since placebo effects are psychological, their effects can be noticed in the time it takes your brain to notice you put them on.
    - cgriswald 7mo ago
pie_flavor 7mo ago
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 7mo ago
  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 7mo ago
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.
- ndkdofococofo 7mo ago
  [dead]
- Barbing 7mo ago
  >inspired me to do a control experiment Delightful, see ya the 27th!
  - lisper 7mo ago
    So the results are in, and I haven't actually noticed much of a change. Last night I went to sleep after 11 and woke up at 5:30. So apparently night shift by itself doesn't have much of an impact one way or the other, at least not in a week.
    - Barbing 7mo ago
      Maybe a few weeks or months… or nevers, who knows! Thanks for the update :)
- gowld 7mo ago
  > 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 7mo ago
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 7mo ago
  > 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.
wa008 7mo ago
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 7mo ago
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-blocking-glasses-work-best https://www.blublocker.com/blogs/news/what-blue-light-blocki...
- kb9alpp 7mo ago
  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.
- stuckonempty 7mo ago
  Those glasses state that they are the only pair that “blocked 100% of harmful blue light in the 400-450 range” But melanopsin contained in the cells that regulate circadian rhythms have an absorption spectrum extends to slightly beyond 540 nm (see the OP’s post). As the author says, “It’s not sensitive to blue, it’s sensitive to cyan (and blue and green).” Those glasses probably do what they say in terms of wavelengths they filter, but they are only partially filtering out light relevant for circadian rhythm regulation and sleep.
cptskippy 7mo ago
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 7mo ago
> 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.
- hinkley 7mo ago
  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.
- EA-3167 7mo ago
  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.
zcw100 7mo ago
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.
- nandomrumber 7mo ago
  I like to use the yellow anti-insect lights for the external lighting around my house as they tend to attract way fewer flying insects and fewer spiders as a result. I also like them in lamps inside for illumination during the evening, with the added benefit of not requiring more IoT devices.
- Marsymars 7mo ago
  This is especially nice if you use bulbs that get warmer as they dim. (See the Kruithof curve.)
deleted 7mo ago
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TACIXAT 7mo ago
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 7mo ago
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 7mo ago
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 7mo ago
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 7mo ago
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.
- Marsymars 7mo ago
  I don't know enough to defend the study, but I don't think 15 minutes of sleep is insignificant. If I'm consistently woken up 15 minutes before my normal wake time it's going to have a negative effect on me.
baud9600 7mo ago
I added the “Noir” extension to mobile Safari, now I automatically get dark mode on all websites including Hacker News.
- hinkley 7mo ago
  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.
- the_pwner224 7mo ago
  "Dark Reader" does the same thing on desktop Firefox/Chrome/etc. (& mobile Firefox, maybe also available on mobile Safari?).
  - baud9600 7mo ago
    Mobile Safari only does this for sites that implement dark themes (and when you have dark mode enabled in iOS). But many sites don’t have these themes. The Noir extension seems to fix the problem for now. There is a reader mode that can go dark but it’s manual, per article
    - the_pwner224 7mo ago
      I see. Not a Safari user myself. On Firefox & Chrome Dark Reader can force its own dark theme even if the site doesn't provide one. Like Noir does on mobile Safari.
james_marks 7mo ago
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.
hn_throwaway_99 7mo ago
I found the basic premise of this blog post to be incredibly flawed. The author seems very sure of himself that blue light filters don't work, but making arguments related to cell types and emissions spectra and circadian rhythms is not the way to make a conclusive argument in a topic like this. Science is littered with recommendations about things that "plausibly" made sense, but that turned out to be flawed or just absolutely wrong when actually put to a real, scientific test. One example most people are familiar with: the recommendation against eating eggs in the 90s was based on the fact that eggs have a lot of cholesterol, and we knew high LDL levels in blood were associated with a greater risk of vascular and heart problems. So, "logically", it seemed that limiting dietary cholesterol would reduce heart disease. Except when scientists actually tested those recommendations, they turned out to be largely wrong - when you eat a lot of cholesterol, for most people their body's natural production of cholesterol goes down, so unless you're in the small subset of people who are particularly sensitive to dietary cholesterol, eating eggs is fine. Making recommendations based solely on a theoretical mechanism of action is bad science. The only way to actually test this is with a study that looks at different types of light restriction and its effect on sleep. Obviously it's kind of impossible to do a blinded study for blue light filters, but you could get close by testing various permutations of light changes (e.g. total luminescence, eliminating only very specific wavelengths, etc.) As another commenter said, it may be a placebo effect, but if it is, who cares? All I care about is that I get a better night sleep, and as someone (unusual among programmers I know) who really doesn't like dark mode, a screen reddener greatly helps me at bedtime.
- guelo 7mo ago
  But you could make your same argument for the pro blue light filter side.
  - hn_throwaway_99 7mo ago
    Sure, and I'd write the same thing if we were talking about a blog post that said everyone should use blue light filters because of some plausible physical mechanism.
- galangalalgol 7mo ago
daneel_w 7mo ago
In summary blue light filters actually do work, through the indirect action of reducing overall light output, but the author has a larger axe to grind about the "technical details" (it's worth reading the article). The warmer color temperature reduces strain on my eyes, which I find both soothing and invaluable.
- MBCook 7mo ago
  The author showed that Apple‘s implementation only cuts two colors by roughly 50%. And given we perceived light non-linearly aren’t they right that that really doesn’t make much of a difference? If someone put up an article saying “Turning down your headphones 1% will help stop hearing loss!“ most people are going to ignore it. OK yeah technically it will, but not to any meaningful amount.
  - daneel_w 7mo ago
    So which do you think it really is? Cutting two wavelengths' outputs in half, or reducing them by a mere 1% as per your trifling comparison?
  - unparagoned 7mo ago
    And when you combine that on top of dark mode and dimming screen that does make a real difference.
scythe 7mo ago
The argument about luminance ranges is wrong. I measure the brightness of monitors regularly as part of my job, and typical maximum luminance values are in the range of 100-500 lux. That puts you right in the steep range of the visual response (especially if you are turning it down and near a max of 100), which is natural — maximizing the slope of the neuronal response to light means that more information will be available to the brain. In fact a good monitor will be tuned according to the just-noticeable difference which aims precisely to maximize the information available according to this characteristic curve. See e.g. the DICOM standard: https://dicom.nema.org/medical/dicom/current/output/chtml/part14/chapter_3.html https://dicom.nema.org/medical/dicom/current/output/chtml/pa... The author's basic problem is that he knows too much about the brain and not enough about monitors. The author goes on to argue that you should be turning your brightness down, but most people already are turning their brightness down; the blue light filter is more comfortable. He does make a reasonable case that you should be reducing green light similarly, but people prefer the incandescent effect of the flux filter to a straightforward color filter — indeed a primary design goal of these filters has been to be pleasant to look at which is why people use them.
SubiculumCode 7mo ago
I get frustrated with my dim and red shift app that is the default on my android phone for neither being very red nor very dim...but it's the type of app where every scammy body will put a red shift app whoch sucks up your location, contacts, etc, so I haven't changed.
zdc1 7mo ago
I recall studies showing that reading in poor lighting conditions is a cause of myopia in children. So I'm questioning whether we want to be reducing luminance on our devices at all. I like my (warm-coloured) lights and screens set to max brightness. I find it's easier to read and lets me work with more distance from the screen. But what about easier sleep? Could we exercise more? Leave screens out of the bedroom? I have no idea.
- zargon 7mo ago
  Significant outdoor exposure is essentially the only relevant factor for preventing myopia. I would be interested in seeing any studies that showed any meaningful relevance of low light reading, while controlling for time spent outdoors.
  - avadodin 7mo ago
    Main factor is genetics. I was gaming on a blurry CRT and reading on a dim light while hardly ever going outside during my teens and I only have light myopia on one eye. I don't know if it has ever been studied, but I suspect eye socket morphology from my own family anecdata. large eyes + small socket = squashed eyes. It could be different genetic factors for different populations too.
    - deleted 7mo ago
      [deleted]
    - zargon 7mo ago
      I agree that genetics can protect you from developing myopia. For people who are genetically susceptible, outdoor exposure is critically important. Most people won't know which group their children are in.
      - avadodin 7mo ago
        Let's just say I knew soon enough for the ones that were in the myopic group. It's not that I don't believe these studies or that I don't recommend children and even adults going outdoors and trying to watch something far away without glasses whatever their supposed genetics may be but I think it is nowhere close to a silver bullet.
buggymcbugfix 7mo ago
> That’s all great, but there are websites that still don’t have dark modes. Such as that very website? ;)
Melatonic 7mo ago
Best thing to actually do is use as dim a screen as possible closer to sleep. You can do this with external monitors using DDC and actually directly control the physical backlight of multiple monitors. Also properly color calibrate your monitors
icar 7mo ago
I actually get head ache after a long session in front of my computer, but putting anti blue light glasses it goes away or never happens.
lloeki 7mo ago
> Is half a lot? > No. Human light perception works on a log scale, allowing us to maintain useful vision over 6 orders of magnitude of luminance, from the sun at noon to moonless nights, whereas halving is .3 orders of magnitude. In relative terms, halving light is a tiny blip of the dynamic range of vision. Kind of missing the point that: a) a display emits spectacularly less light than the sun, even on very overcast days b) said "blue light" reduction is presumably intended to happen at night where 1) any comparison with the ability to maintain unsaturated vision in plain sun on a clear day is largely irrelevant and 2) backlight itself is typically lower than in daylight (not for OLED which does PWM) So given that the amount of artificial light to not screw up with sleep is about equal to "none at all" I'll take a cut in half of what essentially constitutes a flashlight aimed straight at my retinas any day. > Here are four things that can help. [...] Use dark mode [...] found reductions in luminance ranging from 92% to 98%! That’s huge. From my anecdotal experience dark mode and other low contrast themes are mostly used by people who set their brightness too high, and conversely people switching to dark mode immediately crank brightness up. Countless discussions I had: "my battery holds poorly" "using dark mode?" "yes" "try light mode" "but my eyes!" "turn brightness down" "done. wow I just reclaimed 1-2h of battery"
metalman 7mo ago
my phone has a buried setting for ultra dim, which does help, except outside, where it makes the phone unuseable, and then it's impossible to do the 5 taps and scroll to find it, fuck android going to a linux phone
duttish 7mo ago
This is just my own anecdotal experience but I usually get tired around 2130-22 but a few times I've turned off the red filter for various reasons (photo editing etc) and suddenly I'm still there at 0030-01. I'm not saying it's like this for everyone, but it seems to work very well for me at least.
artzev_ 7mo ago
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pvtmert 7mo ago
Interesting take for me is that melatonin (over-)usage can be severely harmful for the individuals. ... over-the-counter melatonin supplements can contain anywhere between 10 to 30 times as much melatonin as is optimal to maintain circadian hygiene. If you have ever taken melatonin and got immediately knocked out cold, had weird dreams and woke up in the middle of the night sweaty or shivering, you likely took too much—which, to be clear, is not your fault, it’s the default in the US and Canada. The mega-doses in stores serve as hypnotics (punches you to sleep), but wreck sleep architecture. The right dose is ~0.3 mg, which is hard to find in pharmacies but can be found online.
- IAmBroom 7mo ago
  > The right dose is ~0.3 mg, I've heard this before, but the only metastudy I could find strongly supports a dose of 3 mg 3 hours before bedtime. Dose effectiveness effectively halves when taking less than ~2 mg or more than ~10 mg. https://onlinelibrary.wiley.com/doi/10.1111/jpi.12985 https://onlinelibrary.wiley.com/doi/10.1111/jpi.12985
xmodem 7mo ago
> 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. The writer is dismissing this out of hand but to me this sounds like a great idea.
pvtmert 7mo ago
My overall take (elephant in the room): Blue light filters don't work, it depends on what you do & how you do it. For example, most people keep watching/scrolling Instagram Reels and TikTok videos. They keep stimulating the brain constantly, not just at electrical level but also in emotional/chemical level too. I have seen people who are addicted and cannot get rid of the addiction. This is not only the dopamine-boost, it has deeper connections of neuro-chemical stimuli. Just observe around you; people pick up their phone to directly open Insta/TikTok, start scrolling right away every 5-10 seconds. (watching stories included too) This is to some extent that when you mention even the possibility of such addiction and abnormal behavior, one gets outright resistance and denial of addiction itself. Much like substance abuse... My point is, majority of the population watches/scrolls these, needing 10g of melatonin to fall asleep. Obviously if I get engaged in an interesting stuff continuously, the existence of blue light does not matter that much. It matters if/when I am reading a novel which is in a mediocre chapter where nothing that interesting going on. The existence of blue-light or lack thereof may tip the scale at that point.
rcore 7mo ago
> That’s all great, but there are websites that still don’t have dark modes. It doesn’t make any sense in 2026 that Gmail doesn’t have a dark mode. If the activity you’re doing most at night is reading email, you might consider an alternative email client. This reads funny on a website that does not respect your device's dark mode. Guess I'll look for an alternative blog.
jedberg 7mo ago
>It doesn’t make any sense in 2026 that Gmail doesn’t have a dark mode I've been using dark mode on gmail for years, not sure what OP is talking about here. But also, my sleep quality got much better when I turned on f.lux. And it got better still when I added a second light to my bathroom that can do a 1800K super-warm light (that's also very dim). And as an added pro-tip, I use f.lux during the day to cut my color temp to 5900K (instead of the default 6500K) and it made a huge difference for how long I could work without getting tired eyes.
snowhale 7mo ago
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234 points by pminimax 7mo ago

snet0 7mo ago

But have you considered that it feels better?

stronglikedan 7mo ago
so do placebos
- kurthr 7mo ago
  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 7mo ago
  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 7mo ago
    Placebo and “manifesting”—the latter sounds mockable but pretty much the same thing, harmless if helpful so hey!
    - nickthegreek 7mo ago
      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 7mo ago
      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 7mo ago
  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 7mo ago
  and? placebo is often effective.

debo_ 7mo ago

> 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.

nine_k 7mo ago
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.
loloquwowndueo 7mo ago
What did you do to tackle your insomnia?
- smt88 7mo ago
  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_ 7mo ago
    That was my experience as well.
- m3047 7mo ago
  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.

koalacola 7mo ago

Is this your article OP?

aethrum 7mo ago

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?

smohare 7mo ago
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thenewnewguy 7mo ago
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 7mo ago
  >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 7mo ago
    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.

socalgal2 7mo ago

[flagged]

pier25 7mo ago

> 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 7mo ago

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.

culi 7mo ago
I have an accessibility shortcut to turn my screen greyscale with triple taps but I kept turning it off so I could see the clues on sudoku and now I've forgotten I even had this for almost a year Low brightness is great though. I didn't realize most of the battery drain on a phone is often just the screen. Lowering the brightness to as little as I need has been great for battery life

cjbgkagh 7mo ago

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 7mo ago

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 7mo ago
>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 7mo ago
  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 7mo ago

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.

IAmBroom 7mo ago
Yes! Leave me and my mercuric-laudanum tooth-straightening sales alone! People like the taste!

ctbeiser 7mo ago

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 7mo ago
Note that it's only 50% if you don't normalise back to absolute brightness.

nicoburns 7mo ago

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 7mo ago
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 7mo ago

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 https://a.co/d/0dISg7oa (0.3mg, this is what I personally use) and go up from there, slowly.

SoftTalker 7mo ago
So buy 5mg, and split the tablet in half.
- Groxx 7mo ago
  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 7mo ago
    Oops, missed the decimal position!
  - IAmBroom 7mo ago
    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 ...).

ltbarcly3 7mo ago

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 7mo ago

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 7mo ago
(just nothing from Goop)
tartoran 7mo ago
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 7mo ago
  You can test the negative easily, but the positive is harder. Thus: placebos.
  - tartoran 7mo ago
    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 7mo ago
      That's reasonable: it works for you. But be aware that, since placebo effects are psychological, their effects can be noticed in the time it takes your brain to notice you put them on.
  - cgriswald 7mo ago

pie_flavor 7mo ago

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 7mo ago
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 7mo ago

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.

ndkdofococofo 7mo ago
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Barbing 7mo ago
>inspired me to do a control experiment Delightful, see ya the 27th!
- lisper 7mo ago
  So the results are in, and I haven't actually noticed much of a change. Last night I went to sleep after 11 and woke up at 5:30. So apparently night shift by itself doesn't have much of an impact one way or the other, at least not in a week.
  - Barbing 7mo ago
    Maybe a few weeks or months… or nevers, who knows! Thanks for the update :)
gowld 7mo ago
> 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 7mo ago

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 7mo ago
> 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.

wa008 7mo ago

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 7mo ago

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-blocking-glasses-work-best https://www.blublocker.com/blogs/news/what-blue-light-blocki...

kb9alpp 7mo ago
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.
stuckonempty 7mo ago
Those glasses state that they are the only pair that “blocked 100% of harmful blue light in the 400-450 range” But melanopsin contained in the cells that regulate circadian rhythms have an absorption spectrum extends to slightly beyond 540 nm (see the OP’s post). As the author says, “It’s not sensitive to blue, it’s sensitive to cyan (and blue and green).” Those glasses probably do what they say in terms of wavelengths they filter, but they are only partially filtering out light relevant for circadian rhythm regulation and sleep.

cptskippy 7mo ago

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 7mo ago

> 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.

hinkley 7mo ago
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.
EA-3167 7mo ago
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.

zcw100 7mo ago

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.

nandomrumber 7mo ago
I like to use the yellow anti-insect lights for the external lighting around my house as they tend to attract way fewer flying insects and fewer spiders as a result. I also like them in lamps inside for illumination during the evening, with the added benefit of not requiring more IoT devices.
Marsymars 7mo ago
This is especially nice if you use bulbs that get warmer as they dim. (See the Kruithof curve.)

deleted 7mo ago

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TACIXAT 7mo ago

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 7mo ago

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 7mo ago

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 7mo ago

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 7mo ago

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.

Marsymars 7mo ago
I don't know enough to defend the study, but I don't think 15 minutes of sleep is insignificant. If I'm consistently woken up 15 minutes before my normal wake time it's going to have a negative effect on me.

baud9600 7mo ago

I added the “Noir” extension to mobile Safari, now I automatically get dark mode on all websites including Hacker News.

hinkley 7mo ago
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.
the_pwner224 7mo ago
"Dark Reader" does the same thing on desktop Firefox/Chrome/etc. (& mobile Firefox, maybe also available on mobile Safari?).
- baud9600 7mo ago
  Mobile Safari only does this for sites that implement dark themes (and when you have dark mode enabled in iOS). But many sites don’t have these themes. The Noir extension seems to fix the problem for now. There is a reader mode that can go dark but it’s manual, per article
  - the_pwner224 7mo ago
    I see. Not a Safari user myself. On Firefox & Chrome Dark Reader can force its own dark theme even if the site doesn't provide one. Like Noir does on mobile Safari.

james_marks 7mo ago

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.

hn_throwaway_99 7mo ago

I found the basic premise of this blog post to be incredibly flawed. The author seems very sure of himself that blue light filters don't work, but making arguments related to cell types and emissions spectra and circadian rhythms is not the way to make a conclusive argument in a topic like this. Science is littered with recommendations about things that "plausibly" made sense, but that turned out to be flawed or just absolutely wrong when actually put to a real, scientific test. One example most people are familiar with: the recommendation against eating eggs in the 90s was based on the fact that eggs have a lot of cholesterol, and we knew high LDL levels in blood were associated with a greater risk of vascular and heart problems. So, "logically", it seemed that limiting dietary cholesterol would reduce heart disease. Except when scientists actually tested those recommendations, they turned out to be largely wrong - when you eat a lot of cholesterol, for most people their body's natural production of cholesterol goes down, so unless you're in the small subset of people who are particularly sensitive to dietary cholesterol, eating eggs is fine. Making recommendations based solely on a theoretical mechanism of action is bad science. The only way to actually test this is with a study that looks at different types of light restriction and its effect on sleep. Obviously it's kind of impossible to do a blinded study for blue light filters, but you could get close by testing various permutations of light changes (e.g. total luminescence, eliminating only very specific wavelengths, etc.) As another commenter said, it may be a placebo effect, but if it is, who cares? All I care about is that I get a better night sleep, and as someone (unusual among programmers I know) who really doesn't like dark mode, a screen reddener greatly helps me at bedtime.

guelo 7mo ago
But you could make your same argument for the pro blue light filter side.
- hn_throwaway_99 7mo ago
  Sure, and I'd write the same thing if we were talking about a blog post that said everyone should use blue light filters because of some plausible physical mechanism.
galangalalgol 7mo ago

daneel_w 7mo ago

In summary blue light filters actually do work, through the indirect action of reducing overall light output, but the author has a larger axe to grind about the "technical details" (it's worth reading the article). The warmer color temperature reduces strain on my eyes, which I find both soothing and invaluable.

MBCook 7mo ago
The author showed that Apple‘s implementation only cuts two colors by roughly 50%. And given we perceived light non-linearly aren’t they right that that really doesn’t make much of a difference? If someone put up an article saying “Turning down your headphones 1% will help stop hearing loss!“ most people are going to ignore it. OK yeah technically it will, but not to any meaningful amount.
- daneel_w 7mo ago
  So which do you think it really is? Cutting two wavelengths' outputs in half, or reducing them by a mere 1% as per your trifling comparison?
- unparagoned 7mo ago
  And when you combine that on top of dark mode and dimming screen that does make a real difference.

scythe 7mo ago

The argument about luminance ranges is wrong. I measure the brightness of monitors regularly as part of my job, and typical maximum luminance values are in the range of 100-500 lux. That puts you right in the steep range of the visual response (especially if you are turning it down and near a max of 100), which is natural — maximizing the slope of the neuronal response to light means that more information will be available to the brain. In fact a good monitor will be tuned according to the just-noticeable difference which aims precisely to maximize the information available according to this characteristic curve. See e.g. the DICOM standard: https://dicom.nema.org/medical/dicom/current/output/chtml/part14/chapter_3.html https://dicom.nema.org/medical/dicom/current/output/chtml/pa... The author's basic problem is that he knows too much about the brain and not enough about monitors. The author goes on to argue that you should be turning your brightness down, but most people already are turning their brightness down; the blue light filter is more comfortable. He does make a reasonable case that you should be reducing green light similarly, but people prefer the incandescent effect of the flux filter to a straightforward color filter — indeed a primary design goal of these filters has been to be pleasant to look at which is why people use them.

SubiculumCode 7mo ago

I get frustrated with my dim and red shift app that is the default on my android phone for neither being very red nor very dim...but it's the type of app where every scammy body will put a red shift app whoch sucks up your location, contacts, etc, so I haven't changed.

zdc1 7mo ago

I recall studies showing that reading in poor lighting conditions is a cause of myopia in children. So I'm questioning whether we want to be reducing luminance on our devices at all. I like my (warm-coloured) lights and screens set to max brightness. I find it's easier to read and lets me work with more distance from the screen. But what about easier sleep? Could we exercise more? Leave screens out of the bedroom? I have no idea.

zargon 7mo ago
Significant outdoor exposure is essentially the only relevant factor for preventing myopia. I would be interested in seeing any studies that showed any meaningful relevance of low light reading, while controlling for time spent outdoors.
- avadodin 7mo ago
  Main factor is genetics. I was gaming on a blurry CRT and reading on a dim light while hardly ever going outside during my teens and I only have light myopia on one eye. I don't know if it has ever been studied, but I suspect eye socket morphology from my own family anecdata. large eyes + small socket = squashed eyes. It could be different genetic factors for different populations too.
  - deleted 7mo ago
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  - zargon 7mo ago
    I agree that genetics can protect you from developing myopia. For people who are genetically susceptible, outdoor exposure is critically important. Most people won't know which group their children are in.
    - avadodin 7mo ago
      Let's just say I knew soon enough for the ones that were in the myopic group. It's not that I don't believe these studies or that I don't recommend children and even adults going outdoors and trying to watch something far away without glasses whatever their supposed genetics may be but I think it is nowhere close to a silver bullet.

buggymcbugfix 7mo ago

> That’s all great, but there are websites that still don’t have dark modes. Such as that very website? ;)

Melatonic 7mo ago

Best thing to actually do is use as dim a screen as possible closer to sleep. You can do this with external monitors using DDC and actually directly control the physical backlight of multiple monitors. Also properly color calibrate your monitors

icar 7mo ago

I actually get head ache after a long session in front of my computer, but putting anti blue light glasses it goes away or never happens.

lloeki 7mo ago

> Is half a lot? > No. Human light perception works on a log scale, allowing us to maintain useful vision over 6 orders of magnitude of luminance, from the sun at noon to moonless nights, whereas halving is .3 orders of magnitude. In relative terms, halving light is a tiny blip of the dynamic range of vision. Kind of missing the point that: a) a display emits spectacularly less light than the sun, even on very overcast days b) said "blue light" reduction is presumably intended to happen at night where 1) any comparison with the ability to maintain unsaturated vision in plain sun on a clear day is largely irrelevant and 2) backlight itself is typically lower than in daylight (not for OLED which does PWM) So given that the amount of artificial light to not screw up with sleep is about equal to "none at all" I'll take a cut in half of what essentially constitutes a flashlight aimed straight at my retinas any day. > Here are four things that can help. [...] Use dark mode [...] found reductions in luminance ranging from 92% to 98%! That’s huge. From my anecdotal experience dark mode and other low contrast themes are mostly used by people who set their brightness too high, and conversely people switching to dark mode immediately crank brightness up. Countless discussions I had: "my battery holds poorly" "using dark mode?" "yes" "try light mode" "but my eyes!" "turn brightness down" "done. wow I just reclaimed 1-2h of battery"

metalman 7mo ago

my phone has a buried setting for ultra dim, which does help, except outside, where it makes the phone unuseable, and then it's impossible to do the 5 taps and scroll to find it, fuck android going to a linux phone

duttish 7mo ago

This is just my own anecdotal experience but I usually get tired around 2130-22 but a few times I've turned off the red filter for various reasons (photo editing etc) and suddenly I'm still there at 0030-01. I'm not saying it's like this for everyone, but it seems to work very well for me at least.

artzev_ 7mo ago

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pvtmert 7mo ago

Interesting take for me is that melatonin (over-)usage can be severely harmful for the individuals. ... over-the-counter melatonin supplements can contain anywhere between 10 to 30 times as much melatonin as is optimal to maintain circadian hygiene. If you have ever taken melatonin and got immediately knocked out cold, had weird dreams and woke up in the middle of the night sweaty or shivering, you likely took too much—which, to be clear, is not your fault, it’s the default in the US and Canada. The mega-doses in stores serve as hypnotics (punches you to sleep), but wreck sleep architecture. The right dose is ~0.3 mg, which is hard to find in pharmacies but can be found online.

IAmBroom 7mo ago
> The right dose is ~0.3 mg, I've heard this before, but the only metastudy I could find strongly supports a dose of 3 mg 3 hours before bedtime. Dose effectiveness effectively halves when taking less than ~2 mg or more than ~10 mg. https://onlinelibrary.wiley.com/doi/10.1111/jpi.12985 https://onlinelibrary.wiley.com/doi/10.1111/jpi.12985

xmodem 7mo ago

pvtmert 7mo ago

My overall take (elephant in the room): Blue light filters don't work, it depends on what you do & how you do it. For example, most people keep watching/scrolling Instagram Reels and TikTok videos. They keep stimulating the brain constantly, not just at electrical level but also in emotional/chemical level too. I have seen people who are addicted and cannot get rid of the addiction. This is not only the dopamine-boost, it has deeper connections of neuro-chemical stimuli. Just observe around you; people pick up their phone to directly open Insta/TikTok, start scrolling right away every 5-10 seconds. (watching stories included too) This is to some extent that when you mention even the possibility of such addiction and abnormal behavior, one gets outright resistance and denial of addiction itself. Much like substance abuse... My point is, majority of the population watches/scrolls these, needing 10g of melatonin to fall asleep. Obviously if I get engaged in an interesting stuff continuously, the existence of blue light does not matter that much. It matters if/when I am reading a novel which is in a mediocre chapter where nothing that interesting going on. The existence of blue-light or lack thereof may tip the scale at that point.

rcore 7mo ago

> That’s all great, but there are websites that still don’t have dark modes. It doesn’t make any sense in 2026 that Gmail doesn’t have a dark mode. If the activity you’re doing most at night is reading email, you might consider an alternative email client. This reads funny on a website that does not respect your device's dark mode. Guess I'll look for an alternative blog.

jedberg 7mo ago

>It doesn’t make any sense in 2026 that Gmail doesn’t have a dark mode I've been using dark mode on gmail for years, not sure what OP is talking about here. But also, my sleep quality got much better when I turned on f.lux. And it got better still when I added a second light to my bathroom that can do a 1800K super-warm light (that's also very dim). And as an added pro-tip, I use f.lux during the day to cut my color temp to 5900K (instead of the default 6500K) and it made a huge difference for how long I could work without getting tired eyes.

snowhale 7mo ago

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