Thanks, that is good to hear about the iPad 9, should be fine with it, was wondering about 9 and 10. Thanks again.
I will chime in and say that I am oddly sensitive to different screens as well for reasons not completely understood- and last year I picked up a 10th gen iPad and it was pretty bad. I didn't get headaches or eye pain, but my eyes would- within minutes of looking at it each time- get super dry, feeling irritated as if I had a sun burn on my eyes, and it would last for some time after using it.
And it is odd because that iPad has no PWM, and it does not have the P3 color space (it's sRGB, so in theory no temporal dithering).
I had returned it within about a week.
Just a month ago I bought a 9th gen on sale, and wanted to give it a try. It's mostly been fine for me, just occasional minor bouts of the dry eye thing, but otherwise really good.