Blue-light filtering spectacles probably make no difference to sleep quality | Hacker News Reader

Blue-light filtering spectacles probably make no difference to sleep quality

medicalxpress.com

62 pointsclumsysmurf37 comments

Yeah, none of these glasses filter out anything close to "all" blue light, because nobody would buy them if they only had red+green color vision.

As an aside, there was some time in the recent past where blue antireflective coatings on eyeglasses were popular. I actually had to make a special request for the old purple/green coating for a few years, because the blue reflections were so distracting while working in an office with overhead fluorescent lights. Many years have passed since that trend and modern coatings seem more blue-ish than purple/green, but they aren't distracting at all. I'm actually shocked how little light modern lenses reflect at all.

I didn't understand how people could claim they have "blue light blocking glasses" with clear lenses. I can literally see the blue light coming through it!

I think Gunnars was early to the market and they actually have amber tint. Before that I would buy amber tinted safety glasses meant for working with lasers. I still take these on trips if I'm staying somewhere unfamiliar... You don't know if the place is going to have hideous harsh blue-white LEDs. Fortunately most places have figured out the need for comfortable warm lighting. All the computer operating systems have a built-in night mode too. I stopped short of putting an amber film over the Kindle...

I have some blue-light blockers which I use only in bed, when reading before going to sleep. They are bulky with 'side boards' to block light, and they turn everything into a sort of orange, undifferentiated hellscape.

The upside is that they seem to work, the downside is that it really only works if you're at a point in your day where you're ONLY looking at text.

A couple of months ago we had some neighbors over, a couple and their two sons, for an early dinner in the back yard.

They just got back from a family vacation, and one of the sons showed me some photos he took on his iPhone.

The photos were in focus and well composed, but everything had a strong orange cast. They almost reminded me of Kodacolor negatives [1] but of course they were positives, not negatives, just very orange.

I meant to ask if he was using some artistic filter or manual white balance, but I figured "he's having fun showing his pictures, let him run with it."

Then the other son showed some photos on his phone, and they were orange too!

It wasn't until later when I got a glimpse of their mom's phone that I realized what the problem was. She didn't have a photo on the screen, just some text or a web page that would have a white background.

You guessed it, that was orange too. And I finally realized they all had Apple's Night Shift turned on.

Well, if nothing else, this gives me a good excuse to get together with them again so I can see their photos as they were meant to be seen. :-)

[1] https://web.archive.org/web/20101128030127/http://photo.net/...

>get together with them again so I can see their photos as they were meant to be seen. :-)

Let's be honest. You don't care about seeing the photos, you just relish the chance to correct their "mistake." :-D

As someone who keeps Night Shift on 24 hours a day for eye comfort (actually 23 hours and 57-ish minutes per day; the as-always anti-user Apple doesn't permit you to turn it on 24 hours a day), it sounds like they might have their Night Shift slider a tad too high.

Personally, I set it at about 60%. Whites don't look orange, but they're no longer radioactive eye-melting blue. :)

And yes, I do occasionally use blue-reducing eyewear. The ones I purchased are visibly tinted yellow, because I understand (basic) color theory!

> Spectacles that are marketed to filter out blue light probably make no difference to eye strain caused by computer use or to sleep quality, according to a review of 17 randomized controlled trials of the best available evidence so far.

This seems like a highly misleading summary of what the meta-analysis showed, or rather, didn't show. "There is no proof that it works" somehow transmutes into "this proves it doesn't work". They are not the same.

The joke about Cochrane Review meta-analyses is that the answer is always, "more research is required", and this looks like another example: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...

First, they find too few studies to meta-analyze. So how can they show that it "probably makes no difference to sleep quality", as the headline screams? Let's go through their comments:

Depression: the quoted CI is "‐33.95 to 53.47". You could drive a truck through that, and most of those values would be practically important. This is just uninformative.

Critical flicker fusion: no one cares, so any numbers don't matter.

Daytime alertness: too few studies / uninformative, so they provide no numbers.

Sleep quality: 3 RCTs hit statistical-significance for benefits, 3 did not (did the 3 have point-estimates for benefit? unspecified), they decline to meta-analyze the 6 together to provide an actual number. ("Potential effects on sleep quality were also indeterminate, with included trials reporting mixed outcomes among heterogeneous study populations.") If this shows anything, it shows that blue-filtering spectacles probably make a difference to sleep quality...

Adverse effects: some anecdotal evidence, no numbers.

Various other metrics: not reported enough to discuss.

So, this is largely completely uninformative, except for the one metric "sleep quality" where they explicitly contradict the headline. ('Indeterminate' does not mean 'probably makes no difference to sleep quality'!)

Medicalxpress screwed this one up.

Yesterday's New York Times article about this: https://www.nytimes.com/2023/08/17/well/live/blue-light-glas...

https://gembared.com/blogs/musings/the-best-daytime-white-li...

> Do white LEDs really exist that are low in blue light, balanced with red, low flicker, and low EMF? ... especially for LEDs, we want lower Kelvin which helps minimize the blue light that many people have had issues with LEDs in the past. For this review we mostly selected 2700K LEDs as it usually has a natural feeling balanced spectrum that is lower in Blue light. But for office areas during the daytime the 3000K versions might be better.

Without Gunnars I can look at a display for 5 hours before eye strain sets in, with Gunnars I can look for 12 hours. So either they used shoddy lens/filters or I am just special somehow.

Placebo effect, maybe?

Maybe. We also need to know whether they have a non-tinted but still "computer glasses" control. I think computer glasses have other tweaks specifically for viewing screens.

Well Gunnars are actually amber tinted. At the end of TFA it says, "Filtering out higher levels of blue light would require the lenses to have an obvious amber tint, which would have a substantial effect on color perception."

This implies that they studied lenses that aren't tinted, which obviously can't be that effective...

> which would have a substantial effect on color perception.

Our vision system is pretty good at compensating for white balance. What I've noticed is with reduced higher wavelengths, my visual acuity drops substantially.

These glasses may not improve sleep quality, but my experience is that it increases sleep quantity as looking at a white display keeps me awake longer like it's still daylight hours, where as with reduced blues my body tends to think it's near bedtime and I do tire and hit the sack sooner.

Yeah exactly. The way I explain it to people is that the orange light lulls you into wind down mode the same way that stepping outside on a sunny morning peps you up.

Try lowering the brightness of your monitor.

My screen glasses help with eye strain, but they were $80 and not $15. The orange backlight in my Kindle is also easier to look at in the dark than the white backlight. Maybe it works for some people and not others.

Not sure about the effectiveness in "lens-form" but the dimming that apps like f.lux and on mobile definitely feel like they help turn down the harshness of bright displays in dark rooms. I have sworn by those apps for like 20 years. It's just like using dark mode. "Easier on the eyes". Less strain on the muscles.

Phone/computer apps actually reduce the blue substantially and visible, unlike the nearly-transparent lenses in the article.

Research from Curtin University (or Flinders) here in Australia did this research years ago.

The greater impact from using our phones at night was not the blue light, but the content you are doom scrolling is designed to engage your brain and stimulate you, which is the opposite of what you want when you are going to bed.

That may be true. But for people like me who have good eyesight and don't need glasses, they provide a socially acceptable way to wear cool-looking glasses in the workplace.

One of these "Blue blocker" coatings was $10 to add to my $400 (sticker price "$1400" because luxotica is a fucking racket) glasses. I knew there was little real research on such a thing, but in the moment I guess I didn't really care about wasting a couple bucks. Very unlike me really.

I can't actually tell that there's anything different about them.

I've been getting increasingly fed up with the US optical services and the slow feedback loop. For the price of a pair of glasses I could get this [1] and just choose my prescription however I like!

[1] https://www.amazon.com/UCanSee-Optical-Trial-Metal-Aluminum/...

That's because there's only one or two companies out there that actually have anything to do with our (US) optical health services.

"...one of the many powerful functions of names such as Ray-Ban (which is owned by Luxottica) or Vogue (owned by Luxottica) or Prada (whose glasses are made by Luxottica) or Oliver Peoples (owned by Luxottica), or of outlets such as LensCrafters, the largest optical retailer in the U.S. (owned by Luxottica) or Sunglass Hut (owned by Luxottica), is to make the marketplace feel more varied than it actually is."[1]

[1] https://theweek.com/articles/784436/secretive-megacompanies-...

The fun part is, Luxotica makes the lenses, and they also run the "insurance" provider for most Eye care stuff, so when they say "These glasses are $1400 but with our insurance you only pay $400!" what they are actually doing is artificially inflating the "sticker" price, so it looks like they are giving such a huge discount, while they charge $400 for five cents worth of plastic and ten cents worth of machine time on a completely automated grinding machine. Keep in mind, when you get those same lenses from like zenny for ten bucks, they're still making a pretty good profit margin.

Basically Luxotica is trying to turn the eye health care market into the same system we have in the normal health care market here in the states, and congress has turned a blind eye to them.

I have some with a genuine yellow tint to them and they helped me with eyestrain with the shitty monitors at my last job. Sleep cycle I don't really care about, but the eyestrain effect was not a placebo. Some monitors just burn out your eyes.

Several years ago, I bought a pair of eye-glasses that could filter blue light. But my eye-sight got worsen. Maybe it was attributed to my bad eye using habitat.

Do these glasses prevent you from fully waking up? Indoors environment wirh little light, also block the blue light and you can be sleepy all day.

Have you ever noticed that B(lue) and G(reen) are the center most frequencies of the visible spectrum—VIBGYOR? If the human eye is naturally adapted for blue skies and green forests, how could the blue wavelength ever be harmful to our eyes? Those are the healthiest frequencies our eyes “consume!”

So much bullshit is marketed these days that it is impossible to sleep well.

Where did you go to school? It's ROYGBIV you monster!

Endianness strikes again.

Well the theory behind it doesn’t say „blue is unhealthy or harmful“ but „blue is daytime“.

Hence the idea to filter out blue at times when there is no blue sky in nature (aka at night).

Moonlight and starlight are blue-biased. There is very little red or green light at night...

I'm just regurgitating the theory, I'm not saying I'm buying into it... ;)

In my personal experience (anectdata), the effects are very neglibable (to the degree they might be placebo)

Circadian rhythms are primary drivers for various hormones in your body (e.g. melatonin, body temps, cortisol levels). These rhythms are tightly tied to external/evolutionary triggers. Yours body resets its internal clock* based on external cues, the strongest of which are eating and exposure to daylight. Since we don't have little clocks saying it's 6:05 in our heads, the body uses blue light hitting the retinas as a proxy. It's the knock-on-effects of having misaligned cortisol levels (which further induce lack of sleep / stress) that are the problem, not the blue light.

*The natural rhythm of each individual differs, hence the cave/space experiments where some people naturally fall into a ~25h cycle [due to lack of external cues]).

During most of the evolution of our genus bright blue or green light meant it was daytime and hence time to be awake. But the red light from fires would often be present when our ancestors were sleeping. It isn't that you should avoid bright blue or green light in general, it's that you should avoid it for maybe an hour or so before you go to bed until when you want to wake up.

> But the red light from fires would often be present when our ancestors were sleeping.

I don't believe this is related. I believe it's simply that blue is the best/easiest/earliest color. The circadian rhythm is ancient, used by bacteria, plants, and mammals [1], long before humans had fire. Blue is most energetic, and is all that can be seen in the depths of the ocean, where life mostly likely originated.

[1] https://schaechter.asmblog.org/schaechter/2023/04/sensing-bl...

We have way better receptors for dark and bright, so for that color reception isn't necessary.

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