Severe Sensitivity to Light Emitted from LED-Backlit Displays

[MagnuM]

As an update, I'm back to the drawing board, and back to my Dell U2410 (CCFL). My last update where I mentioned how my brain/body "put up" with a problematic display over time did a hairpin turn one day where I suddenly felt very hot and unwell and felt like I would pass out or puke or something. I had bought the Dell P2425 LED-backlit IPS on June 20th, invoiced June 22nd, received it in shipping June 26th. I tried to return it on July 23rd after that bad neurological episode, but Dell refused the return saying my 30-day return policy had elapsed. They claimed that the clock starts on your invoice date, not when you receive the monitor. Talk about false advertising. Won't be bothering with that company again. Here I tried to be patient and try to find a solution when I should have just reboxed this thing and sent it back to them. Now I have to try to sell it for a loss.

You're absolutely right that our species has not looked a light source other than those produced by black body radiation sources such as the sun, fire, lanterns, candles, incandescent lightbulbs, etc, up until only a few decades ago when fluorescent lighting was introduced (and gave some poor susceptible people migraines). People have correctly pointed out that there is a lot of blue light emitted from the sun. However, I don't have any problems from the sun or being outside. I only have problems on LED-backlit computer monitors. Perhaps it is because there is such a sharp spike in the blue range which isn't balanced out by all the other colors? I heard that our eyes/brain will essentially take the average of a color spectrum when looking at the color white (which might explain why whites look so "blue" from LED light like harsh car headlights).

I guess I should remind myself not to get stuck on a story or theory to keep bias in check when experimenting. I'm so sure that blue light is causing my neurological symptoms, even though the more recent studies suggest that blue light does not cause eye strain. I do counter back with "does it cause 'brain strain'?" though.

Take the curious case of the user Jason38 here. They are the only user that described my issue basically perfectly. They suffered these symptoms for over a decade like I did, but they seemed to have it even worse than I did. They had to wear these dark orange SCT glasses just to use any monitor. I bought a pair. They are so aggressive that a pure yellow square on a white background will be completely camouflaged because the white background is as yellow as the square is. Does it cut down my symptoms on an LED? Sure does, but at a cost.

The user above hasn't posted for years because they solved their issue and likely went on with their life. They purchased a ViewSonic XG270 monitor, and they mentioned that they can use the monitor 16 hours a day if they wanted to without issues, and without the dark orange SCT glasses above. Looking at the specs of this monitor, it makes 0 sense why this monitor is working so amazingly well for them. Perhaps the dark orange SCT glasses were a red herring all along for all we know, and blue light was only part of the answer. All I can tell you from what I have read is that the ones that had the most success did so by pure trial-and-error, trying the most amount of monitors they could, until one worked. When they found the one that worked, they did not know why it worked, and frankly did not care.

The more recent scientific studies did agree that blue light does seem to affect sleep though. Oddly enough, I don't really seem to notice any affects on my sleep. I can use a computer right up to when I hop into bed and fall asleep without much difficulty. Perhaps it is affecting the quality of my sleep though for all I know.

I also have no issues with sunlight or looking at a pure blue sky. I don't really need shades to be outside. I want to stress that I really only have issues with computer monitors backlit by an LED. Similar less intense symptoms can be reproduced on this Dell U2410 CCFL if I increase the brightness from 0% to 50%. I will do this purposefully for color-sensitive work, put up with the pain and brain-strain symptoms, and revert back to 0% when I'm done. The problem with trying to put an LED monitor to 0% that I have found is that it is so dark and dim that I can barely see anything, while 0% on this Dell U2410 is still surprisingly bright (especially at night).

You are right that perhaps the reason I don't seem to have much issues with phones and TVs is FOV (field-of-view). The binocular vision therapy office that I'm currently attending pointed this out as well. The phone is small, so there are much other non-phone things my eyes and brain see while using it. Same with a TV in the distance. A computer monitor though is like... right there taking up most of what you see, so that's a lot of directional light coming at ya from pretty close. A good test for me honestly would be using a TV at a distance, because I haven't tested that for 8+ hours a day before.

Basically I'm trying to find the root cause of my sensitivity to be able to plan for the future properly. I know my Dell U2410 won't last forever, and neither will all other CCFLs.

[MPRT|GTFO]

I only have problems on LED-backlit computer monitors. Perhaps it is because there is such a sharp spike in the blue range which isn't balanced out by all the other colors? I heard that our eyes/brain will essentially take the average of a color spectrum when looking at the color white (which might explain why whites look so "blue" from LED light like harsh car headlights).

It's not simply one average. A more detailed understanding about how the spectrum is sensed and processed may be relevant for your case. You can check the Wikipedia article section Color_vision#Physiology_of_color_perception, or at least the cone cell response spectra chart there:

Normalized response spectra of human cones to monochromatic spectral stimuli, with wavelength given in nanometers

Cone-fundamentals-with-srgb-spectrum.svg.png (28.87 KiB) Viewed 9282 times

Basically, each cone type (Short, a.k.a. "blue", Medium, a.k.a. "green" and Long, a.k.a. "red") actually responds to a large portion of the visible spectrum that overlaps with the others (e.g. green light is detected to some degree by all photoreceptors, not just the M-cones). So, each cone type will produce its own different signal value which is like a weighed average (more like integral math, actually) of the spectrum of the light received. And then to determine the color at a given point, nerves process signals coming from the nearest S, M and L cones: it is the ratios of the signal values coming from the different cone types that matters. But there are different ways to achieve a given combination of signals.

So display and lighting engineers, as usual, want to have more relaxed requirements when they can, and so they assume they don't need to produce a broad, flat spectrum to produce a white color (like what incandescent bulbs do, which approximate black body radiators). Apparently they assume that as long as the ratio of the S:M:L signals produced is mostly right for most individuals, the spectrum is good enough. One weakness in making this assumption is due to the fact that the response spectra of human cones (see the chart above again) are actually not exactly the same for every individual. There are separate genes that code the S, M and L response spectra, respectively. For each of these genes there are at least a couple of different variants that produce a curve that is slightly offset to the left or right of the other variants. Black body radiation of any temperature is going to be perceived pretty much the same regardless of these genes. However, once you start playing with spiky light spectra you can end up with ones that trigger very different combinations of S:M:L signals between individuals with different cone pigment genes. That's why colors on a monitor can look correct or nice to one individual and incorrect or ugly to another. But I suspect that it also means that, for some individuals some monitors can look unnatural enough to become an irritant, especially when their light comprises most of the light that is coming in. There could be many other things about the physiology that we don't fully understand, and which could be complicating the reaction to unnatural spectra.

So, I'd be researching the light spectra of monitors, as per your leading theory. I'd be comparing both the overall shape and the wavelength of the peak(s) and trying to find something much different from the known bad ones. I don't know which monitor and panel/backlight manufacturers even provide such data, other than cases mentioned earlier in the thread. I guess some products targeted at professionals are more likely to be engineered for a flatter spectrum, and to advertise such a feature, because that must be a way to achieve good color accuracy as perceived by more of the population. Or I'd be looking directly for professional experience or scientific theories linking light spectra to neurological symptoms. I hope you figure out something.

[Tisik]

Did you try a TN screen? I have a Zowie BenQ ZOWIE XL2540K - 240Hz | Full HD | 24,5'' | TN which helped me get rid of any motion sickness or headaches.