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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

#281
post #249
post #238

Earlier quoted context omitted.

So those cyan LED's have a forward voltage drop of 3.2-3.6 volts. So you'd be looking at a 32V-36V 350ma power supply or thereabouts to hook them up in series. If it were me, I'd probably run everything in parallel just to keep the voltages lower, and be able to use readily available power adapters. Aliexpress has a PWM controlled constant current driver that takes 5-35V in and outputs 350ma max [1]. 10 of them are $…

Just tested with my power supply, and the minimum V_on seems to be about 2.7V. So if I want to drive all 10 in series, I'll need 30V+. If I had three banks in a 4,3,3 configuration, I could get away with a 12V power supply as well, which would be nice since I already have a bunch of 12V 5A wall warts. I already got the board you linked, supposedly configured for 700 mA. Haven't tested yet. The datasheet for the part…

Why do you want to drive the 10 LEDs in series?

Re: Chemists discover how blue light speeds blindness

#282
post #130

I wear computer glasses at all times when working, and highly recommend them. It greatly reduces eye strain, and filters blue light. If anyone is looking for a good pair, I buy mine from Gunnar [0] (no affiliation). [0] https://gunnar.com/

what about EagleEyes? Does anybody have experience with these?

Blue light blocking: https://www.eagleeyes.com/pages/blue-light-blocking

Computer sunglasses https://www.eagleeyes.com/pages/digital-eye-protection

Re: Chemists discover how blue light speeds blindness

#284
post #77
post #32

Earlier quoted context omitted.

Because of the way your eyes work. If it is bright, your pupil will be shrunk, to not be blinded by the luminosity. When it is dark, your pupil will be opened wide up. It is this principle that camera apertures are based on. Now if you have your pupil wide open in a completely dark environment and put a 100% brightness screen at ~10cm of your eyes, what do you expect will happen ? Our eyes are made for nature, that m…

The same happens with computer screens. Most offices are under-lit (or over-lit but only if ALL your UI has a dark background). To get a feel for this, point your cell phone at your desk area and take a picture (without HDR enabled). If you can't take a picture without over– or under–exposing the screen or the wall, then your setup is putting strain on the eyes.

This is absolute quackery.

Your camera's cell phone barely manages to hold approximately eight stops of latitude. Blowing out that pathetic dynamic range has no grounding in relation to any notion of "eye strain".

Re: Chemists discover how blue light speeds blindness

#285
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…

Hi herf, your software is really nice but one thing that kept me from using it (and adopted since Apple's 'night shift', though I don't use all days) is that I enjoy photography. Probably you heard this a few times, but one thing that I'd love to have is this off for photos (I'd switch from being an eventual user to being a full-time user).

Re: Chemists discover how blue light speeds blindness

#286

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…

Just speculating here, but I‘d say since eyes have evolved to also look at the sky, I’d say no. Shining a laser on cells is different from sunlight in various ways. First, laser light waves are coherent (perfectly overlapping), so their effect might amplify A LOT. The dosage (J/cm) used by the researchers also might be 100x as high as the sun‘s, for all we know. Then, there’s the thing that sunlight is a mixture of a very broad range of frequencies, from far infrared (and below, microwaves etc) up to ultraviolet (and beyond, eg X-rays, which luckily don’t arrive at the earth surface in huge doses). Again, just speculating, but near infrared has been found to have a beneficial effect on retinal diseases, so maybe it compensates for the problems blue light creates.

Re: Chemists discover how blue light speeds blindness

#287

Earlier quoted context omitted.

Can you be more specific about "severe eyestrain"? E.g. if there is pain, where? Eyes dry, red? Difficulty focusing? Peripheral vision? Have you had an eye exam when the strain is present? When the strain is present, what happens if you switch to reading paper? Or switch to distance vision, e.g. looking out the window? How long does it take to recover from the strain when reading or looking into the distance?

The severe issue for the last 5-6 months since trying to use LED panels has been a tingling/tightness sensation around cheeks/nose that spreads to back of head/neck/trapezius turning into pain/ache. If you clench your eyes/face and lean forward you can feel the neck/upper back tighten too and it's all that area which makes me think something is triggering eye muscles to the degree they are making me tense everything…

I have no idea why the new displays would be different, but I did discover at one point that medication can affect eyes in surprising and wierdly lighting-device specific ways. In my case, I found that phenibut was causing a light therapy visor to hurt my eyes even on low, although strangely even fairly bright natural light did not. Even without phenibut I have trouble with the visor on high (a ReTimer that I got due to it being more greenish). Later I learned that taurine transpoters can also transport GABA and I suspect that this might have something to do with it (and that people who use high amounts of phenibut for long periods of time may be causing permanant eye damage via retinal taurine depletion). If you are taking medication and are able to try something else for a little while, there is at least a small chance that could help.

You may have tried this, but if it is muscle related then massaging your face and/or upper back might help. Not pushing, but grabbing and slowly twisting the muscles or skin. E.g. put three fingers at the bottom of your eye socket and bring your thumb up so it is an inch or a little less away from your second finger, then push your thumb up and fingers 3 and 4 down. You can repeat the same basic twisting motion over much of your face. Another one is grab skin/muscle between your thumb and two fingers and tilt towards the two fingers. Just lifting muscles (as tilting towards your thumb can sometimes do, or grab and lift) can also be quite helpful.

In the back of the neck and upper back it is easier to twist the muscle (but avoid the sides of the neck where there are fragile nerves) and additionally skin rolling can be helpful where you put two or three fingers opposite the flat side of your thumb, grab a small amount of skin (and potentially muscle too, although your focus should be on the skin) and then walk your thumb forward with your fingers, such that there is a raised area that moves in front of your thumb. If it feels "crunchy" at all or feels like it is sticking to the muscle (that you can't lift the skin as easily as elsewhere), go over it again until it doesn't, although not necessarily all at once since it can be exceptionally painful in some cases (in that case, just do a little each day and it should eventually not be painful). The twisting can usually be done in a way that affects just the skin or the muscle as well and both can be helpful.

Those three techniques (twisting or lifting muscles and twisting or rolling skin) are IMO the most useful ones anywhere on the body you can do them (also don't get too close to most joints), but just applying pressure to muscles doesn't really help in my experience. Lifting muscles on your own back is hard and not necessarily worth aiming for. For the face another good technique if you can is to put down your middle three fingers and keep them in one spot on your skin while moving your hand rapidly within a quarter inch or so of that spot.

The muscle/skin adherence particularly tends to happen on legs, most of all upper legs but often both, although the upper back/shoulder area is another area it frequently happens. If you see a massage therapist, look for Shiatsu, Tui-Na, or (not exclusively stretching focused) Thai massage since those styles are more focused on this kind of thing. But there may be quite a bit you can do yourself (depending on your other issues) that can be helpful. I guess it is unlikely to fix the real issue here but might at least help you recover faster.

Re: Chemists discover how blue light speeds blindness

#288

Earlier quoted context omitted.

I assume you mean the night light button in the action center? If so I would argue f.lux does a lot more. For one thing you can choose the hue it goes to, but also unlike the Windows 10 one which (AFAIK) is simply on/off, f.lux will adjust based on a schedule which means that you don't typically notice the effects (as the change happens slowly). This, combined with the ability to change damn near every parameter it u…

Both macOS and Windows 10 has on/off now, scheduling, less/more warm adjustment. Windows 10 even has sunset to sunrise based on location. EDIT: HN is becoming more like Reddit every day, I see. Ridiculous. Down-voted for pointing out the existence of helpful features. EDIT: might have been my fault.

Just checked. Also Mac OSX has Sunset to Sunrise based on location.

Re: Chemists discover how blue light speeds blindness

#290
post #285
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…

Hi herf, your software is really nice but one thing that kept me from using it (and adopted since Apple's 'night shift', though I don't use all days) is that I enjoy photography. Probably you heard this a few times, but one thing that I'd love to have is this off for photos (I'd switch from being an eventual user to being a full-time user).

You can just disable it for an hour. That's what I do at least.
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