Blue light filters don't work – controlling total luminance is a better bet
37 points
2 hours ago
| 20 comments
| neuroai.science
| HN
aethrum
2 hours ago
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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?

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tartoran
1 hour ago
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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.

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cellularmitosis
5 minutes ago
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Can you elaborate on “no way back”?
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KaiserPro
1 hour ago
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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.

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cpburns2009
56 minutes ago
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Blue light filtering lenses come at a premium. You don't accidentally get them.
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KaiserPro
53 minutes ago
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I wasn't paying for them, so it was very much accidental.
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mikkupikku
1 minute ago
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You should go back and demand they be replaced. Such a mistake isn't something you should tolerate.
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pavel_lishin
51 minutes ago
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Someone ran up to you and put them on your face?
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robinsonb5
1 hour ago
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If you wait long enough cataracts will give you that for free.
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thenewnewguy
1 hour ago
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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).

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geoduck14
1 hour ago
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>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

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thenewnewguy
1 hour ago
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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.

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jack_pp
1 hour ago
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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.
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thenewnewguy
1 hour ago
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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.

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jack_pp
1 hour ago
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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.
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crazygringo
1 hour ago
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> 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.

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bob1029
1 hour ago
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> 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

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taco_emoji
1 hour ago
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> 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.

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pclowes
1 hour ago
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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!

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tartoran
1 hour ago
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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.
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Barbing
1 hour ago
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(just nothing from Goop)
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lisper
1 hour ago
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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.

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gowld
1 minute ago
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> 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.

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Barbing
1 hour ago
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>inspired me to do a control experiment

Delightful, see ya the 27th!

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harrall
1 hour ago
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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.”

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lowdest
1 hour ago
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>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.

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alejohausner
49 minutes ago
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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...

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snet0
2 hours ago
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But have you considered that it feels better?
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stronglikedan
2 hours ago
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so do placebos
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kurthr
2 hours ago
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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.

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snet0
1 hour ago
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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.
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Barbing
1 hour ago
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Placebo and “manifesting”—the latter sounds mockable but pretty much the same thing, harmless if helpful so hey!
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nickthegreek
1 hour ago
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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.
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tshaddox
1 hour ago
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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).
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allthetime
1 hour ago
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and? placebo is often effective.
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SoftTalker
1 hour ago
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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.
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pie_flavor
1 hour ago
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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.
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Barbing
1 hour ago
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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…

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nicoburns
1 hour ago
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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).
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nomel
1 hour ago
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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.

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ctbeiser
1 hour ago
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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.
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leni536
1 hour ago
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Note that it's only 50% if you don't normalise back to absolute brightness.
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cjbgkagh
1 hour ago
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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.

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koalacola
2 hours ago
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Is this your article OP?
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Groxx
1 hour ago
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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.

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SoftTalker
1 hour ago
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So buy 5mg, and split the tablet in half.
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Groxx
1 hour ago
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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.

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SoftTalker
56 minutes ago
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Oops, missed the decimal position!
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pier25
1 hour ago
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> 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?

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wa008
53 minutes ago
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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.
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crazygringo
1 hour ago
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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't either.

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cptskippy
48 minutes ago
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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.
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ltbarcly3
1 hour ago
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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.
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mikkupikku
1 hour ago
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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.
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debo_
2 hours ago
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> 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.

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kqr
2 hours ago
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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.
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jerlam
2 hours ago
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Yeah, "get better sleep" is usually followed with "by buying this thing". No one makes any money if you go to sleep earlier.
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debo_
1 hour ago
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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.
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nine_k
2 hours ago
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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.
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loloquwowndueo
2 hours ago
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What did you do to tackle your insomnia?
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m3047
1 hour ago
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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.

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debo_
1 hour ago
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Which herbs do you take?
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debo_
1 hour ago
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I spoke about it in this video: https://www.youtube.com/watch?v=QnNPRqLVtaM
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smt88
2 hours ago
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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.
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debo_
1 hour ago
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That was my experience as well.
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