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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

#311

Post by athenot »

foolrush wrote: post #284
athenot wrote: post #77

Earlier quoted context omitted.

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".

> Your camera's cell phone barely manages to hold approximately eight stops of latitude

That's precisely what makes it a decent tool for detecting lighting imbalance. Just because our eyes mask the issue with high perceptual dynamic doesn't mean it's not straining them.

Re: Chemists discover how blue light speeds blindness

#313

Post by nathan_long »

herf wrote: post #256
nathan_long wrote: post #168

I am excited about LED lights for their efficiency, but keep seeing articles like this and don't understand the practical ramifications, like "what bulbs should I buy?" I messaged Cree on Twitter, expecting a very corporate response, but they linked to some studies (which I haven't yet had time to explore.) FWIW - https://www.energy.gov/eere/ssl/street-lighting-blue-light-a... and https://www.lrc.rpi.edu/resources/ne…

The message is: there is no more risk from LED than older sources, by the metrics we have now. I would suggest that one problem is that LEDs don't "warm dim" (unless you get some special ones from Philips and a few others), and people tend to dim them less overall.

What do you mean by "warm dim"?

Re: Chemists discover how blue light speeds blindness

#315

Post by foolrush »

athenot wrote: post #311
foolrush wrote: post #284

Earlier quoted context omitted.

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".

> Your camera's cell phone barely manages to hold approximately eight stops of latitude That's precisely what makes it a decent tool for detecting lighting imbalance. Just because our eyes mask the issue with high perceptual dynamic doesn't mean it's not straining them.

Eight. Stops. Is. Not. High.

Re: Chemists discover how blue light speeds blindness

#316

Post by bb88 »

mafuyu wrote: post #250
bb88 wrote: post #230

Earlier quoted context omitted.

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.

Oh, yeah! Totally forgot about those from high school chemistry class. :) I'm sure there'll be _some_ blue light. I don't know if a prism would be high resolution enough to tell if it's a dangerous level.

Yeah, you won't be able to see the intensity, but you will be able to see what components of the spectrum are there. It's also and easy way to test filters.

Re: Chemists discover how blue light speeds blindness

#317

Post by phyzome »

herf wrote: post #162
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…

If you are curious, the smallest doses where "blue light hazard" has been observed in humans (short-term exposure) are around 10 J/cm^2. International standards use around 2 J/cm^2 for a safety margin. One example of this is hiking in fresh snow for hours, no sunglasses, meaning exposures well above 10,000 cd/m2 to "white light". Computer screens are way dimmer - an hour of iPad use is .0365 J/cm^2. http://www.nature…

Do those numbers account for pupil dilation?

Re: Chemists discover how blue light speeds blindness

#318

Post by opan »

erikbye wrote: post #169
benrbray wrote: post #159

Earlier quoted context omitted.

These are relatively new features, and they arguably wouldn't have been added if not for the popularity of flux ;)

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 would argue that if some software is under a free (libre) license, it's worth using over [non-free] first party stuff. This doesn't apply to f.lux, but does to redshift.

Re: Chemists discover how blue light speeds blindness

#319

Post by opan »

fouc wrote: post #295
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…

I wanted to leave a note for others to keep in mind that f.lux can make the computer screen TOO comfortable to read in the evening. Which can lead to eye strain. I used f.lux for 2 years. I found that I would stay up way past my bedtime, glued to the computer screen, and end up with correspondingly tired & fucked up eyes. So I got rid of f.lux, and after that, I would go to bed at a more proper time. When the screen…

I also tend to have eye strain if I'm computing very late at night, and take it as a signal to go to bed. I've described this to people, and it seems it doesn't affect everyone. It could also just be that there's a difference in awake time, blink frequency, or some other factor. I'll often go to bed more because my eyes are giving up on me and starting to burn rather than any sort of mental fatigue. I don't always keep normal daylight hours, so read this more as staying awake a long time than something specific to daylight

Re: Chemists discover how blue light speeds blindness

#320

Post by hestipod »

dm3730 wrote: post #264
hestipod wrote: post #87

This or something connected to it is literally ruining my last chance at life but I cannot solve it and there is always a catch. I was disabled long ago by bad surgery and left in lots of pain. My physical career was ended. I was denied social assistance and fell in every crack. Life has never been stable enough long enough to reeducate and rebuild. In suicidal desperation I posted in a few places asking for ideas. A…

> reduce their quality of life further by using one of the 2 expensive and limited E-Ink displays out there Could you elaborate on above? I did not understand the logic behind the sentence. E-Ink displays by themselves do not generate any light as they don't have any backlight or light emitter behind the display. That's why they work in bright sunlight. Some products with E-Ink displays have frontlights for night tim…

I was stating that having to use the available E-ink displays is a reduction in quality of life because they are small (13"), expensive (~1000usd), and limited in function and performance which makes most web activities aggravating due to lag and ghosting. They aren't a solution, but just a more difficult workaround that shrinks life even more in my case.
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