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Comment by luqtas | Hacker News Reader

author cites less than 5 studies... one of them measures the effect of melatonin supression with 1 hour of blue light exposure. one of the links they posted studies the effects on rats and here's a segment of it,

>Indeed, direct investigations of human circadian resetting reveal that low-intensity, short-wavelength light (460 nm) produces smaller responses than longer wavelength light (555 nm) of equivalent melanopic illuminance [3]. These data are therefore consistent with the circadian effects of color we identify in mice.

feels like a conclusion out of cherry pick & misunderstanding of stuff they read

https://pubmed.ncbi.nlm.nih.gov/21164152/

https://www.sleepfoundation.org/bedroom-environment/blue-lig...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9424753/

https://www.health.harvard.edu/staying-healthy/blue-light-ha...

https://pubmed.ncbi.nlm.nih.gov/30311830/

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Hi, I'm the author. I read over 20 studies before writing this post and stand by my conclusion: there is not conclusive evidence blue spectrum light specifically is worse than other illumination.

I only linked to the most interesting outliers that could not reproduce the most cited study's findings. I also linked to the most rigorous study (3 groups: using Night Shift, not using Night Shift, not using phone at all in a natural setting instead of lab) with the largest sample size (167 people) and duration (7 consecutive nights) that found no observable benefit from using Night Shift, only not using a phone before bed.

Here's another rigorous study in a lab setting with similar conclusions: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561503/

seriously? the iphone study suggest that users stop "consuming" blue light 1 hour before sleep. they don't even control for other substances like coffee or alcohol intake or medication other than "sleep disorders"... your _robust_ ipad study has 12 people...

one of the links i posted is a meta-analysis on the subject that skimmed down ~ 130 studies down to 15 because bad metodology & conclude that blue light has effect on sleep quality

without digging into all of these, what's the conclusion?

that it's relevant to use a filter/glass after the sunset

or better saying: there's _plenty_ of evidence on blue light supressing melatonin, more than other wavelengths & we know that (melatonin) effects the circadian rhythm, thus, your sleep quality

edit: months ago i was @ a lecture of a neuro-scientist & they talked briefly about melatonin & if i'm not mistaken, changes on your circadian rhythm/sleep patterns don't happen overnight, so blocking blue light/having melatonin pills for a day or a week and expect results aren't the wisest thing to do. but i can't find a paper about this, so take with a grain of salt or ask your closest scientist about it ;)

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