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Chemists discover how blue light speeds blindness

phys.org

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Re: Chemists discover how blue light speeds blindness

#221

Post by antt »

JimboOmega wrote: post #81

I don't quite understand. Blue light - any blue light - causes blindness? So we shouldn't look at the sky even? I've never heard blue being a danger other than its effect on the biological clock, so that seems like a pretty bold claim. Ultraviolet, sure... Though buried in there is something about immune system and vitamin E levels... I really find it hard to believe that blue light exposure is automatically bad. We…

The first thing to realize about any scientific paper is that it's wrong. To a very good approximation all scientific papers are wrong, until the results are replicated a couple of dozen times and failed to be replicated a few times this could well be an artifact of the methods they used.

Never make life changed based on the results of one single study.

Re: Chemists discover how blue light speeds blindness

#222

Post by exhilaration »

rapnie wrote: post #188
tough_luck wrote: post #173

Earlier quoted context omitted.

For my Samsung TV I use movie mode and also change colour temperature to warm.

I have the "blue light filter" on by default, on my android mobile. Don't know how effective it is, but it will at least help a bit.

On my Google Pixel, this is under Settings > Display > Night Light.

Re: Chemists discover how blue light speeds blindness

#223

Post by Vesther »

wpasc wrote: post #156
herf wrote: post #136

f.lux author here, still slogging through the article. It is hard to understand the light levels used because they use "power" (uW, mW) from a laser, and not "irradiance" (uW/cm^2 or mW/cm^2), so which area they have concentrated that light over is hard to understand. All I can see is it is from a laser, so the irradiance could be extremely high. The human lens filters most light at the peak of the given spectrum for…

Thank you for your input, but I mostly want to thank you for f.lux. It has been one of my favorite things for a long time. It's silly how long it's taken companies to provide a native blue light filter and your product just kicks ass. If you guys ever wanted to figure out your app on a smart TV (or apple TV), I know there'd be a lot of thankful people! Also, I'd love to contribute to the ongoing dev of f.lux (I don't…

Check out the FAQ for a PayPal donation link:

https://justgetflux.com/faq.html

Huge thanks to the author from me as well!

Re: Chemists discover how blue light speeds blindness

#225

Post by epmaybe »

jakemauer wrote: post #203
erikbye wrote: post #169

Earlier quoted context omitted.

Does that matter? It's built-in now, and that's why I commented. To raise awareness. If built-in features have you covered there is no point going third-party.

I understand where you're coming from but they don't have feature parity. Flux allows me to target much lower color temperatures than MacOS' built in "Night Shift" feature. That alone makes Flux worthwhile.

out of curiosity, how low are you going in terms of temperature?

Re: Chemists discover how blue light speeds blindness

#226

Post by sc00ty »

chrisper wrote: post #210
mafuyu wrote: post #44

I'm in the process of building a Philips Hue-compatible light therapy LED strip that goes above my bed, and I chose 500 nm cyan LEDs due to this concern. The goal is to have the lights gradually wake me up every morning and help align my sleep cycles, as I suffer from Delayed Phase Sleep Disorder. Figure 3[0] in the paper seems to show that 500 nm is safe, and that melanopsin has high absorption at 500nm, which has i…

Any reason why you are not just buying a Philips wake up light? I have one and it's great. Especially during darker months

How long have you been using yours? I have been using one for about 3 years. Initially it worked great, but it seems the light just doesn't do it anymore and the alarm sounds are what eventually wake me up.

Re: Chemists discover how blue light speeds blindness

#227

Post by jcl »

vosper wrote: post #101
astrodust wrote: post #88

Earlier quoted context omitted.

We have chemical receptors on our tongue and in our nose for poisons. We have neurons that detect pain. Just because we can sense it doesn't mean it's not harmful.

But those receptors signal something unpleasant - a terrible taste, pain. Looking at blue doesn't cause pain or unpleasantness.

I'd guess that the negative effects of blue light over a lifetime might only have become noticeable in modern times, with better vision correction and treatment for conditions like glaucoma and cataracts. If so, there probably hasn't been significant evolutionary pressure to dislike viewing blue light. Also, half of outdoors is blue half the time, so instinctual blue-avoidance would probably hurt survival.

But it is perhaps misleading to concentrate on things that are exclusively blue... The real problem is light containing the relevant range of frequencies, which includes many non-blue colors, due to the relative presence of other frequencies. For example, your eyes would probably absorb much fewer relevant photons when staring at an empty patch of sky than when staring at the sun, even though the sun is not considered blue. And looking at the sun does cause unpleasantness.

Re: Chemists discover how blue light speeds blindness

#228

Post by pishpash »

bcoates wrote: post #61
pishpash wrote: post #11

Earlier quoted context omitted.

It sounds like one should use it permanently, and not just at night. But the real problem is the spectral composition of the synthetic white light on screens. Now I want fluorescent backlights back.

Is there any reason to think that narrowband blue is worse than broadband blue? It makes for poor CRI when used as a light source but if the display blue is near the peak sensitivity frequency for blue it should result in slightly less total power being delivered to the eye than an equivalent blackbody spectrum white light.

Maybe total power isn't what matters and peak sensitivity is also where peak damage is.

Re: Chemists discover how blue light speeds blindness

#229

Post by mafuyu »

chrisper wrote: post #210
mafuyu wrote: post #44

I'm in the process of building a Philips Hue-compatible light therapy LED strip that goes above my bed, and I chose 500 nm cyan LEDs due to this concern. The goal is to have the lights gradually wake me up every morning and help align my sleep cycles, as I suffer from Delayed Phase Sleep Disorder. Figure 3[0] in the paper seems to show that 500 nm is safe, and that melanopsin has high absorption at 500nm, which has i…

Any reason why you are not just buying a Philips wake up light? I have one and it's great. Especially during darker months

I wanted something that was compatible with my existing Hue system, and specifically targeted wavelengths for light therapy.

I already have a normal Hue bulb next to my bed on a schedule, similar to the wake up light, but a light strip right above my head seems more appealing to me.

Re: Chemists discover how blue light speeds blindness

#230

Post by bb88 »

mafuyu wrote: post #146
mark-r wrote: post #139

Earlier quoted context omitted.

Do you have a spectral output chart for those LEDs? You might be surprised how much blue is still in the output.

Yeah, especially with these cheapo Chinese LEDs. I looked into spectrometers, but they seem pretty pricey. Maybe some sort of plastic filter that blocks the shorter wavelengths?

How about a simple prism? That would tell you instantly if there's any blue light in the stream.

Edit: You might need a mask to create a slit of light so you can see the spectrum clearly.

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