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> blue light that damages your vision Can anyone explain to me how looking at a computer screen is not several times less harmful than spending time outside fr
by burke 8y ago
> blue light that damages your vision
Can anyone explain to me how looking at a computer screen is not several times less harmful than spending time outside from a lifetime-blue-light-exposure perspective? The sky is blue and natural light has a blue component in probably about the same proportion as white light from a screen.
Maybe I'm wrong — and I'd like to find out if I am — but this whole blue light scare really just feels like a weird bandwagon.
- TACIXAT 8y agoI think you're right. There was just an article about blue light speeding blindness, but the flux author chimed in and said screens are less than 5% of the hazard weighted irradiance of the sky. [1] I'm not totally sure what that means honestly, but I think we're OK. 1. https://news.ycombinator.com/item?id=17726716 https://news.ycombinator.com/item?id=17726716
- hyperpallium 8y agoThough you don't stare at the sky for hours.
- TACIXAT 8y agoI did on shrooms once. It had some nice patterns because my pupils were so dilated. Thankfully not blind.
- smolder 8y agoI don't think the patterns are from your eyes behavior mainly but rather misfiring nerves directly thanks to the toxin. Noise transformed by visual circuitry into patterns, as patterns are what it deals in on the perceiving end.
- Rapzid 8y agoShrooms don't cause blindness; the sky causes blindness.
- jdietrich 8y agoIt's kind of obvious to anyone who has used a photographic light meter. My computer screen has a peak luminance of about 300cd/m2. A super bright HDR display can achieve peak luminance of about 800cd/m2, which most people find uncomfortably bright in normal viewing conditions. An overcast sky is about 2,000cd/m2 and a clear sky is about 7,000cd/m2. UV is vastly more damaging than blue light and monitors produce negligible amounts of UV.
- bytematic 8y agoRegardless, blinking less often and focusing purely on a 2d image will degrade your vision
- ehnto 8y agoI found my vision vastly improved when I started riding and hiking a lot more. It also drastically degrades when I am tired, to the point where if I am well rested and have been active that week I don't need glasses. I tend not to use them at all anymore. Interestingly I never experienced the same benefits from driving, even though there is some eye movement and shifting focus there.
- specialist 8y agoThe light & vision story is still being discovered. "How is the idea of "outdoor time" used for myopia control? One of the big surprises of recent research is the importance of how increased time spent outdoors helps in preventing myopia. At the present time it appears that 14 hours a week or more outdoors are significantly effective in reducing myopia progression." http://www.myopiaprevention.org/outdoor_time.html http://www.myopiaprevention.org/outdoor_time.html
- cimmanom 8y agoI thought the reason outdoor time is recommended for myopia is that it causes you to focus your eyes on objects at greater distances that aren’t available indoors.
- wiml 8y agoIt's also a lot brighter outdoors than it is indoors (we're really good at adapting to different light levels, so it doesn't seem like a large change, but it is). Recently I've read that simply being in a brighter environment has effects on the way your eyes develop when you're young.
- smolder 8y agoThat remains as a very plausible (IMO) hypothesis but is not rigorously proven, afaik. It's sort of a tough one to prove. So they're being conservative and not guessing here.
- smolder 8y agoTo clarify WHY I think it's very plausible: There is of course a lot of data connecting indoor time and myopia. There is also a muscle which controls the curvature of the lenses in our eyes to adjust focus to different depths. Not using this mechanism in a "normal" way, across its full range and with regularity, stands out as the important factor of the indoor time link, since it's most directly related to focusing.
- 8y ago
- Izkata 8y agoI've always read it as the ratio being wrong for our eyes - that the light is simply too high energy, and it needs to be balanced out with red light or filtered away. Sunlight, despite having a much higher amount of blue light, also has more light across the rest of the spectrum, reducing the difference and making it less harmful.
- rb808 8y agoA cloudless blue-sky day has a lot of blue as well. I haven't heard its bad for you, even if the warm sunset light is prettier.
- Pica_soO 8y agoRealistically- how much time do you, when walking a landscape, really actively look on the sky? https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/222479/ET4S2018_09_Misthos_PDFA.pdf?sequence=1&isAllowed=y https://www.research-collection.ethz.ch/bitstream/handle/20.... https://www.sciencedirect.com/science/article/pii/0169204695002081 https://www.sciencedirect.com/science/article/pii/0169204695... Turns out, surprisingly little. And we perceive environments, where we can not see the sky at all (forests) as quite relaxing.
- kevin_thibedeau 8y agoThe original claim is that exposure after sunset upsets your circadian rhythms. Now it's been twisted into "OMG! blue light will blind you". The good news is that this will hopefully put the nail in the annoying blue indicator LED coffin. All the cool kids are using white and RGB LEDs now.
- smolder 8y agoI think blue light causing gradual vision damage is actually a more recent and separate claim that just also happens to villify blue light.