Yes, I did not mean to imply that it would be the culprit for you. I was only talking about myself and my experiences. For me it is absolutely, scientifically proven. I've had so many monitors where there is PWM at some other brightness percentage than 100% and we've done double blind testing with my wife. (It is impossible to know visually if the backlight is at 99 or 100, but my eyes get red only when it is at 99%.
I also have used my Surface Pro 2 for 3 years now and many times in frustration have tried to set the brightness to something else than 100 and without fail it irritates my eyes.
Now I'm very careful when I'm saying that my Z2 is now causing me eye strain as I do not have any explanation for it, except the claims that Marhsmallow changes something in how the display driver works.
In fact, as I've explained in some other posts, I've experienced some additional eye strain due to dieting and it could easily be the case that the Z2 would have always irritated my eyes in this setting when my eyes are more prone to eye irritation. But of course, the reason for the irritation is still unclear. I cannot detect a PWM in that screen, so then what is it? This HPZR40W that I use at home does not cause any irritation what so ever, no matter how long I use it or how irritated my eyes are due to some other irritant.
It would be very interesting to know if some of those people who experience irritation due to windows version or display adapters, would try this display and see if it irritates them or not. I think we would really need kind of scientific results on what really irritates and what not.
It would be very interesting to understand why some colours irritate you (like gray, I think you said somewhere?)
I mean, PWM is easy to understand. A flickerling light which in fact can be sometimes even visible - why would it not irritate? But a colour? Do you get irritation from a, say gray wall when lit with natural light?
Please do not take this as if i'd doubt you, I'm just trying to get to the bottom of this. Maybe I'm headed there as well