I originally used an iPad for some years but also for the same period suffered severe mental fatigue, which even got to the point of seeing my doctor and trying antidepressants. I was unable to make a link between the two until I eventually replaced it with a Surface Pro 3 (for drawing) and immediately felt the feeling lift.
It was as if there was something in the light from the iPad which was wasn't the case with the Surface which made my mind foggy and nauseous, as if I've been looking into a lamp for too long. While I used the iPad I had tried screen filters and reducing the light to its absolute minimum, which had no noticeable effect.
I have also constantly used computer screens at work and at home every day, though these seemed to be okay.
I'd like to think it's something as simple as the difference between LCD and LED screens, though it seems complicated as LCD screens apparently also use LED backlight. There also seems to be the issue of screen flicker speed. Does anyone have a simple technical explanation of what might be making the difference?
Read more: https://ipadget.com/talk/cases/can-some-digital-screens-cause-more-fatigue-than-others.html