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  • soundstar3 Level 1 Level 1 (0 points)

    Im also going to try rubylith as a screen filter.

  • mojarvinen Level 1 Level 1 (0 points)

    Suggestion - why not try the blue blocking glasses like those Uvex glasses that you can buy from Amzaon for $5?

     

    That way one could be sure that no blue light enters the eye,  (daylight, ceiling lights etc.)

     

    I have those, but those do not make any difference.

     

    But I've used those for circardian rythm synchronizing - the topic is big in the biohacking scene.

     

    I'd bet my money on blue light not being the problem for any of us, unless the person also suffers symptoms when being outdoors on a clear sky day.

  • tfouto Level 1 Level 1 (0 points)

    morjavinen,

     

    it's better you to stay on a intention to bet, and not bet for real, because you would loose your money.

     

    It's totally diferent, the spectrum of light of a clear sky and a led screen.

     

    Clear light it's a flat spectrum. All the cones of the eye are receiving the same amounts of light. The processing of color in the brain is even.

     

    On a led screen, the light is basically almost blue part of the spectrum at a high energy. The green and red are much lower. The blue cones are the most stimulated. And the problem is that the eye has much less blue cones than green or red. Much, much less. I suppose the blue cones are much more sensitive, or the brain processing the blue is more efective. Maybe the processing of light in brain with such an uneven spectrum of light is problematic for some.

     

    The problem is just not the blue light, it's the totally uneven distribution of light. That's the difference between a clear light and a LED screen. It's the relationship between the amount of total light received by all cones and the blue ones... A world of difference...

     

    For all the list of people complaining here there seems to be two different kind of causes here at least.

     

    I have monitors with a PWM with low frequencies and i dont have a problem with it for more then 10 years a use that monitor.

  • Dovez Level 1 Level 1 (0 points)

    I used to have problems looking at any invisibly flickering light, but was convinced blue light was the problem. Found a material that blocked all blue and most of the green part of the spectrum as well. Well, instead of the pain comming in 10 seconds it came in a minute or two. Didn't solve the problem at all, just made it a tiny bit more comfortable. The blue thing is overrated. Sure, it can be a factor to some degree, but it's just blown out of proportions here. It's a conveniant explanation, nothing more. I'm sure if you did some tests, like removing the screen in a PWM-free display and looking at the flicker-free backlight directly after reducing it to a comfortable brightness level, you would feel it's not a problem to look at it. You say: "I just don't buy the whole screen pixels having consciously undetectable flickering thing.". Well, check it, if you want to know for sure! I saw these flickering pixels with my own eyes when I found the right settings on my cellphone camera and looked through it. But I was somewhat lucky that one of my cameras could detect it. Research flicker and headaches/ eye pain. You will see that the list of your symptoms is identical. You say:"Oh, my monitor has PWM and I can use it. It must not be flicker. It can only be the blue light" Well, there is such a thing as different flicker frequencies. Perhaps the 60 Hz pixel flicker is more troublesome to you than the 200 Hz PWM flicker. Or maybe it's because the pixels flicker so chaotically.

     

    http://www.eizo.com/global/library/basics/eyestrain/#tab03

     

    "When comparing the relationship between LED and blue light, we have confirmed that LED backlights and CCFL backlights have about the same amount of blue light."

     


  • mojarvinen Level 1 Level 1 (0 points)

    This certainly makes this whole problem more interesting and difficult.

     

    The PWM is quite clear and there starts to be some mainstream acceptance, that it is a real problem for many.

     

    Dithering is less obvious and I think so is the blue spectrum.

     

    And then there are people with all kinds of other similar problems, like a friend of mine that cannot look at a screen unless it is at the eye height, without experiencing epileptic seizures.

     

    It's mindblowing that even this thread has been going on for so long, but no clear solution is avaiblable yet, for everyone, that is.

     

    Many years I thought that I was just using the computer too much, like when I was after workday playing games - my eyes would get irritated on a CRT and non LED LCD. Afterwards I discovered that even the LCD which seemingly did not cause problems in moderate use, did have a PWM of 130 Hz. I tolerated moderate use, but now the new especially Samsung panels have 240 Hz, which is not tolerable even for 30 minutes.

     

    It's a mystery though, why my Sony Trinitron CRT irritated my eyes 20 years ago, where some other CRT's didn't at the same refresh rate.

  • Dovez Level 1 Level 1 (0 points)

    mojarvinen wrote:

     

    It's a mystery though, why my Sony Trinitron CRT irritated my eyes 20 years ago, where some other CRT's didn't at the same refresh rate.

    Maybe different phosphor decay times

  • tfouto Level 1 Level 1 (0 points)

    "Found a material that blocked all blue and most of the green part of the spectrum as well." This is not true. It cant block all blue and green. Do you believe in the description of the product? It's impossible to do that...

     

    "Well, instead of the pain comming in 10 seconds it came in a minute or two. Didn't solve the problem at all, just made it a tiny bit more comfortable. The blue thing is overrated. "

     

    That's why it get better but didn't blocked all blue light at all.

  • tfouto Level 1 Level 1 (0 points)

    "I'm sure if you did some tests, like removing the screen in a PWM-free display and looking at the flicker-free backlight directly after reducing it to a comfortable brightness level, you would feel it's not a problem to look at it."

     

    Seeing the kindle paperwhite front-light at max bright is the worst offender to my eyes...

     

    I am glad you are sure for a proof you dont have...

     


  • tfouto Level 1 Level 1 (0 points)

    "Perhaps the 60 Hz pixel flicker is more troublesome to you than the 200 Hz PWM flicker. Or maybe it's because the pixels flicker so chaotically."

     

    If there is a static screen, white screen with letters, The screen dont flicker at 60hz like white, black at 60hz. It just refreshs the white 60 times per second... the same color...

     

    To me flux, does a world of wonders. The more red the screen the better...

  • Dovez Level 1 Level 1 (0 points)

    Okay, if 10 or 5 % of blue light remained, would that be such a problem? How can 10% remaining blue cause 90% of the problem. Do you hear yourself? When I use this material, blue LEDs become almost invisible, kind of gray-looking.

  • tfouto Level 1 Level 1 (0 points)

    So to you it's not a problem, blue-light, that doesn't mean that not a problem to all...

  • Dovez Level 1 Level 1 (0 points)

    tfouto wrote:

     

     

     

    Seeing the kindle paperwhite front-light at max bright is the worst offender to my eyes...

     


    Are you sure it's flicker-free. Another cause could be spatial dithering. Does it bother you without the frontlight? Maybe you've mentioned it before, but I seem to have forgotten. No harm in repeating, right?

  • Dovez Level 1 Level 1 (0 points)

    tfouto wrote:

     

    So to you it's not a problem, blue-light, that doesn't mean that not a problem to all...

    Do the same as me to find out if it's a problem for you

  • Dovez Level 1 Level 1 (0 points)

    tfouto wrote:

     

    The screen dont flicker at 60hz like white, black at 60hz. It just refreshs the white 60 times per second... the same color...

     

     

    The screen doesn't go balck and white, but individual pixels go chaotically from bright to dimm. This is what I understand.

  • Dovez Level 1 Level 1 (0 points)

    tfouto wrote:

     

    To me flux, does a world of wonders. The more red the screen the better...

    Yet it doesn't solve your problem, right?