I found something that i think is very interesting. I have huge trouble working with screens, with exception after replacing the entire screen (cheap one from ebay) of my iphone 5, i was able to start reading the screen for hours. Now i have replaced the glass of my ipad 4 (not original, and replace only the glass where the polarized film is placed) and same thing happened.
I think the solution for me and many of us could be to replace the polarized film (or add a new one). Bellow are some youtube vídeos that show how the polarized film work.
With the polarized film, its possible to complete darken the screen even with 100% brightness, just by rotating the polarized film! After replacing the polarized filter in iphone 5 and ipad 4, colors are more washed and it look there is no/less temporal dithering, it give me no eye pain. Also it's possible to have 100% brightness (no pwm for many monitors) and only very low visible backlight, just by rotating the film).
It's possible to buy cheap polarized film from china to test it. You nedd to choose the size and angle. I suggest to buy a very big polarized filter, to try with several screens. Remember that to find the best angle, the polarized film need to rotate. Im not sure if its necessary to remove the "old" polarized film because i havent try it that way.
Hope you understand my poor english. Thanks