- Edited
andc I know not everyone agrees but I am a firm believer in most cases this is firmly a tech problem, most likely SW which is making the HW do things that hurt, and not an eyesight problem. I believe that because most of us don't have issues with some tech and with paper and daily life. If you have an eye disease or problem it would affect you in more use casest than specific LED displays. I can look at a specific CCFL display on a super old laptop for unhealthy amounts of time like 12-16 hours without eye pain...my back and butt hurts from sitting, but its not straining. But a few minutes on offensive displays sets me off. That's not a medical issue. That's a tech issue in the same way getting sick from a poison doesn't mean you are unhealthy, it means your body can't handle that noxious stimulus.
It "feels" logical that it's movment/flickering since that is tiring to look at in general when its visible, strobes lights etc, that it would be tiring when your eyes/brain can see it but you don't notice it. That also explains why older stuff is often better, its not as capable of as much visual trickery. Nobody is bothered by an ancient LED calculator, but modern computer displays hurt most of us. I have also never seen a case where a fancier or more expensive tech solved the issue. Most of what people can use is older.
For a time I believed PWM was the problem but for myself and many others it's proven not. In fact I have never seen someone state removing PWM/LED/anti-aliasing or any of the others from the equation solved their problem entirely across all devices and OSes. Dithering may or may not be the "real" problem but until we can shut it off and see its all speculation and what does work for us might just be good fortune as the dithering is happening but just not being displayed etc due to HW limits. There just isn't any other obvious culprit at this point. The only people I have seen get better overall are those who say the symptoms just went away, so some people can obvious get used to the noxious thing, but its still clearly happening.