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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 argume

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.

galangalalgol 8mo ago
His argument seems to be that the night modes don't remove much blue. My initial assumption was that it was about physical filters. Yellow or amber 99%+ safety lenses are a thing and several of my coworkers wear them. Looking through them at those painfully bright blue leds makes them appear to be off. Yes everything looks strange, but they work. Likewise a different coworker manually removes all blue in the monitor settings themselves independent of the brightness setting. That also works. The author's assertion should be qualified amd narrowed a bit.
- UlisesAC4 8mo ago
  I can absolutely confirm that night mode works wonders. Since ten years ago I discovered them I no longer have dry eye like problems.
  - stuckonempty 8mo ago
    This is great it works for you but hopefully you realize the weakness of anecdotal evidence when it comes to declaring something is universally effective. Your n of 1 argument is the equivalent of “my grandpa smoked until he was 95 so smoking clearly can’t be bad for your health”.
    - red75prime 8mo ago
      It’s more like, "Some people have something going on that ameliorates the cardiovascular and cancer problems caused by smoking."
    - whateverboat 8mo ago
      I love redshift as well. I actually keep it 24x7, and my eyes don't get tired at all even after 12 hours of programming. Nowadays, turning off redshift feels like an attack on the eyes. And no, reducing brightness on monitors doesn't have the same effect. I recently upgraded my monitors to 600nits brightness from 350nits and there has been no change in comfort level with redshift but without the redshift, the old monitors (and the new) stil feel very hostile to eyes.
    - hn_throwaway_99 8mo ago
      You're right, it's not valid to make any broader conclusions from an anecdote. But it's about just as valid as the author making conclusions based solely on physical "this is what I should expect to happen" hypotheses. More importantly, as an individual, the only thing that counts is when the n of 1 is you. As another commenter said, you don't need to live your life by studies. It's not like there is much expense or risk in trying a screen reddener, so try it out, and if it works for you, great - it's bizarre that the author thinks it is "aggravating" that a lot of people use things that they say work for them.
stuckonempty 8mo ago
Did you read the article? He points out “It’s possible that Night Shift does something, but the biggest study I could find of Night Shift mode (still a pretty small study) found little effect on sleep, so if there’s an effect, it must be tiny.” He links the exact type of observational study you asked for Regardless the maximum possible effect will be constrained by the biology of the cells responsible for responding to blue light. Maybe knowledge of the biology is incomplete or flawed but to not use it to inform what’s possible seems foolish. So what if it’s a placebo effect? Well some people are spending money and time investing in blue light filtering glasses and other solutions. It’s potentially snake oil and it could keep them from pursuing better solutions that would actually help them sleep
- Griffinsauce 8mo ago
  That sentence does not give me a lot of confidence. The conclusion does not follow the initial statement at all.
- hn_throwaway_99 8mo ago
  If the author goes "I couldn't find enough high quality studies on the topic I'm discussing", then the conclusion should be that we need more studies, not to come to unwarranted conclusions in the absence of actual data. > Well some people are spending money and time investing in blue light filtering glasses and other solutions. Ironically, we actually do have a number of good studies on the effects of blue light filtering glasses (easily findable with a Google search) and they do demonstrably reduce onset of sleep time. Where more research is needed is on software-only filters for screens.
  - hogwasher 8mo ago
    If that's the case, I want to see studies on how blue light filtering glasses fare versus just regular-ass sunglasses (of equivalent tint). Is it the reduction of blue light that helps people, or is it just the reduction of light, full stop? Just the latter on its own is quite thoroughly proven to help people sleep, and helps with migraines, and so on. Or what about UV light? I've never seen anyone say that an anti-UV coating/lens material in glasses helps with sleep (nor that it doesn't). But UV is still high frequency light that enters our eyes, even higher frequency than blue light, and there's at least some research to suggest it might affect human circadian rhythms despite its invisibility to us. But I've never seen anyone suggest that wearing your regular glasses (because most regular glasses these days are UV-blocking) before bed, or before a nap during the day (or before trying to sleep through the day, for a night shift worker), could help someone get to sleep. I'd imagine it could also depend on exactly how much blue light is filtered; it's not like all blue light filtering glasses are tinted to the same degree. Glasses that all but make the world look like a reptile house might do a lot more than glasses that have only the faintest of orange tints. It's not like lenses either block blue light fully or don't block it at all; there's a spectrum here. How much blue light is supposed to get blocked for it to matter? Were the studies that showed blue light blocking glasses to improve sleep done with lenses so tinted they were essentially sunglasses, or did they use nearly clear/only slightly tinted lenses akin to the blue light blocking lenses that are marketed as alternatives to regular clear lenses?
guelo 8mo ago
But you could make your same argument for the pro blue light filter side.
- hn_throwaway_99 8mo 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.
energy123 8mo ago
Blue light blockers are a scam that was created when some circadian rhythm research went viral (in a highly misrepresented way) online a few years ago. It's a stunt to make some quick cash from unwitting buyers.
- storus 8mo ago
  My Gunnars give me immediate eye relief after a day of work looking at a display. Are you sure it's a scam?
  - disillusioned 8mo ago
    To the extent that there's some sort of clinical statistically significant lift over, say, however you might control for a placebo here, who knows? To the extent that it's working for you in a meaningful way, placebo or not... does it even matter? If they're working for you, they're tautologically not a scam, except insofar as you find yourself missing out on benefits promised that aren't being realized, or you feel that the price you've paid is disproportionate to the benefit because some much cheaper option exists in some sense. Put another way, placebo or not, if there's an effect, and it's a positive one for you, it really doesn't matter. It's working.
    - 7bit 8mo ago
      The same could be said about homeopathy, but homeopathy is a scam. The problem is, how do you define "if there's an effect"? A placebo can not have an effect, yet, it has.
      - samtheDamned 8mo ago
        The whole point of placebo is that it has an effect though, just not one based on a real change.
        storus 8mo ago
        That won't work for immediate relief; placebo is studied statistically as a cumulative change over a period of time. Not when I put Gunnars over my sore eyes from computing too much and get immediate relief. Frankly, I find this discussion a bit insane, a bunch of people trying to persuade me "it's all in my head" because they align with the opposite opinion, not with reality.
accidentallfact 8mo ago
Even the premise of the idea is wrong, as evenings are either blue from the blue sky, or white from the clouds. It takes exceptional circumstances to have a reddish evening, and even then it's just around the sunset. I guess that it may help people with undercorrected myopia due to the chromatic aberration, but, I don't know.
- gurkenkram 8mo ago
  It is indeed about the sunset and especially the last phases of it. It's also why red light is recommended for night feeding when breastfeeding. Works for me, both reducing the blue light and worked for my baby, too, using only deep orange and red light of a cheap LED color change lamp. Apparently works for many, since red nursing lights are suddenly sold everywhere.
  - Symmetry 8mo ago
    The sunset and also fires. Humans have been making fires for a million years and in addition to allowing us to evolve much smaller guts they've also had time exert pressure on our behavior.
  - philwelch 8mo ago
    I thought red light was recommended for nighttime because it doesn’t interfere with natural night vision.
- bawolff 8mo ago
  When the sun goes down the amount of blue light goes down. Are you disputing that? Respectfully this feels like a crazy claim.
  - DoctorOetker 8mo ago
    Well technically during the twilight right after the sun has disappeared below the horizon, or just before the sun appears from under the horizon (when there is no direct line of sight to the sun), the sky is strictly blue-er: the reason the sun and the neighboring angles in the sky appears "yellow/orange" is because green and especially red scattered less through the atmosphere, while a good portion of blue light scatters much more easily on our atmosphere, allowing non-line-of-sight blue illumination on land where the sun has not yet risen or where the sun has already set. All of humanity has been a witness to these observations and yet we blindly assume blue light filters must have such and such an effect. But even if it did: suppose a modern concrete-cave-dweller has an out of phase shifted day/night pattern with respect to solar rhythm, having blue light as the last form of light actually seems more natural!
mock-possum 8mo ago
Plus there’s a lot of protein eggs, so they’re filling, and have to eat less to feel full, resulting in less food consumed and therefore less opportunity to intake further sources of cholesterol

galangalalgol 8mo ago

His argument seems to be that the night modes don't remove much blue. My initial assumption was that it was about physical filters. Yellow or amber 99%+ safety lenses are a thing and several of my coworkers wear them. Looking through them at those painfully bright blue leds makes them appear to be off. Yes everything looks strange, but they work. Likewise a different coworker manually removes all blue in the monitor settings themselves independent of the brightness setting. That also works. The author's assertion should be qualified amd narrowed a bit.

UlisesAC4 8mo ago
I can absolutely confirm that night mode works wonders. Since ten years ago I discovered them I no longer have dry eye like problems.
- stuckonempty 8mo ago
  This is great it works for you but hopefully you realize the weakness of anecdotal evidence when it comes to declaring something is universally effective. Your n of 1 argument is the equivalent of “my grandpa smoked until he was 95 so smoking clearly can’t be bad for your health”.
  - red75prime 8mo ago
    It’s more like, "Some people have something going on that ameliorates the cardiovascular and cancer problems caused by smoking."
  - whateverboat 8mo ago
    I love redshift as well. I actually keep it 24x7, and my eyes don't get tired at all even after 12 hours of programming. Nowadays, turning off redshift feels like an attack on the eyes. And no, reducing brightness on monitors doesn't have the same effect. I recently upgraded my monitors to 600nits brightness from 350nits and there has been no change in comfort level with redshift but without the redshift, the old monitors (and the new) stil feel very hostile to eyes.
  - hn_throwaway_99 8mo ago
    You're right, it's not valid to make any broader conclusions from an anecdote. But it's about just as valid as the author making conclusions based solely on physical "this is what I should expect to happen" hypotheses. More importantly, as an individual, the only thing that counts is when the n of 1 is you. As another commenter said, you don't need to live your life by studies. It's not like there is much expense or risk in trying a screen reddener, so try it out, and if it works for you, great - it's bizarre that the author thinks it is "aggravating" that a lot of people use things that they say work for them.

stuckonempty 8mo ago

Did you read the article? He points out “It’s possible that Night Shift does something, but the biggest study I could find of Night Shift mode (still a pretty small study) found little effect on sleep, so if there’s an effect, it must be tiny.” He links the exact type of observational study you asked for Regardless the maximum possible effect will be constrained by the biology of the cells responsible for responding to blue light. Maybe knowledge of the biology is incomplete or flawed but to not use it to inform what’s possible seems foolish. So what if it’s a placebo effect? Well some people are spending money and time investing in blue light filtering glasses and other solutions. It’s potentially snake oil and it could keep them from pursuing better solutions that would actually help them sleep

Griffinsauce 8mo ago
That sentence does not give me a lot of confidence. The conclusion does not follow the initial statement at all.
hn_throwaway_99 8mo ago
If the author goes "I couldn't find enough high quality studies on the topic I'm discussing", then the conclusion should be that we need more studies, not to come to unwarranted conclusions in the absence of actual data. > Well some people are spending money and time investing in blue light filtering glasses and other solutions. Ironically, we actually do have a number of good studies on the effects of blue light filtering glasses (easily findable with a Google search) and they do demonstrably reduce onset of sleep time. Where more research is needed is on software-only filters for screens.
- hogwasher 8mo ago
  If that's the case, I want to see studies on how blue light filtering glasses fare versus just regular-ass sunglasses (of equivalent tint). Is it the reduction of blue light that helps people, or is it just the reduction of light, full stop? Just the latter on its own is quite thoroughly proven to help people sleep, and helps with migraines, and so on. Or what about UV light? I've never seen anyone say that an anti-UV coating/lens material in glasses helps with sleep (nor that it doesn't). But UV is still high frequency light that enters our eyes, even higher frequency than blue light, and there's at least some research to suggest it might affect human circadian rhythms despite its invisibility to us. But I've never seen anyone suggest that wearing your regular glasses (because most regular glasses these days are UV-blocking) before bed, or before a nap during the day (or before trying to sleep through the day, for a night shift worker), could help someone get to sleep. I'd imagine it could also depend on exactly how much blue light is filtered; it's not like all blue light filtering glasses are tinted to the same degree. Glasses that all but make the world look like a reptile house might do a lot more than glasses that have only the faintest of orange tints. It's not like lenses either block blue light fully or don't block it at all; there's a spectrum here. How much blue light is supposed to get blocked for it to matter? Were the studies that showed blue light blocking glasses to improve sleep done with lenses so tinted they were essentially sunglasses, or did they use nearly clear/only slightly tinted lenses akin to the blue light blocking lenses that are marketed as alternatives to regular clear lenses?

guelo 8mo ago

But you could make your same argument for the pro blue light filter side.

hn_throwaway_99 8mo 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.

energy123 8mo ago

Blue light blockers are a scam that was created when some circadian rhythm research went viral (in a highly misrepresented way) online a few years ago. It's a stunt to make some quick cash from unwitting buyers.

storus 8mo ago
My Gunnars give me immediate eye relief after a day of work looking at a display. Are you sure it's a scam?
- disillusioned 8mo ago
  To the extent that there's some sort of clinical statistically significant lift over, say, however you might control for a placebo here, who knows? To the extent that it's working for you in a meaningful way, placebo or not... does it even matter? If they're working for you, they're tautologically not a scam, except insofar as you find yourself missing out on benefits promised that aren't being realized, or you feel that the price you've paid is disproportionate to the benefit because some much cheaper option exists in some sense. Put another way, placebo or not, if there's an effect, and it's a positive one for you, it really doesn't matter. It's working.
  - 7bit 8mo ago
    The same could be said about homeopathy, but homeopathy is a scam. The problem is, how do you define "if there's an effect"? A placebo can not have an effect, yet, it has.
    - samtheDamned 8mo ago
      The whole point of placebo is that it has an effect though, just not one based on a real change.
      - storus 8mo ago
        That won't work for immediate relief; placebo is studied statistically as a cumulative change over a period of time. Not when I put Gunnars over my sore eyes from computing too much and get immediate relief. Frankly, I find this discussion a bit insane, a bunch of people trying to persuade me "it's all in my head" because they align with the opposite opinion, not with reality.

accidentallfact 8mo ago

Even the premise of the idea is wrong, as evenings are either blue from the blue sky, or white from the clouds. It takes exceptional circumstances to have a reddish evening, and even then it's just around the sunset. I guess that it may help people with undercorrected myopia due to the chromatic aberration, but, I don't know.

gurkenkram 8mo ago
It is indeed about the sunset and especially the last phases of it. It's also why red light is recommended for night feeding when breastfeeding. Works for me, both reducing the blue light and worked for my baby, too, using only deep orange and red light of a cheap LED color change lamp. Apparently works for many, since red nursing lights are suddenly sold everywhere.
- Symmetry 8mo ago
  The sunset and also fires. Humans have been making fires for a million years and in addition to allowing us to evolve much smaller guts they've also had time exert pressure on our behavior.
- philwelch 8mo ago
  I thought red light was recommended for nighttime because it doesn’t interfere with natural night vision.
bawolff 8mo ago
When the sun goes down the amount of blue light goes down. Are you disputing that? Respectfully this feels like a crazy claim.
- DoctorOetker 8mo ago
  Well technically during the twilight right after the sun has disappeared below the horizon, or just before the sun appears from under the horizon (when there is no direct line of sight to the sun), the sky is strictly blue-er: the reason the sun and the neighboring angles in the sky appears "yellow/orange" is because green and especially red scattered less through the atmosphere, while a good portion of blue light scatters much more easily on our atmosphere, allowing non-line-of-sight blue illumination on land where the sun has not yet risen or where the sun has already set. All of humanity has been a witness to these observations and yet we blindly assume blue light filters must have such and such an effect. But even if it did: suppose a modern concrete-cave-dweller has an out of phase shifted day/night pattern with respect to solar rhythm, having blue light as the last form of light actually seems more natural!

mock-possum 8mo ago

Plus there’s a lot of protein eggs, so they’re filling, and have to eat less to feel full, resulting in less food consumed and therefore less opportunity to intake further sources of cholesterol