I should add the fact, that i like my white on screen to be 10-20 nits. 20 nits is actually very bright for my eyes, at least on a screen that i use for 8 hours. I think a lot of screens are doing a bad job on minimum brightness setting to make a non flickering light. 10 nits is really more of a light grey, but i forget about it after a few minutes of work and the strain is much less.
For some reason the new monitors i tested are always straining me, even on 10 nits, my old 2009 TN-Panel didnt, but it became unusable, because every adapter introduced nausea on my old screen. Perhaps it is not even the adapter, but a driver issue?!
But i am pretty sure there is some "pounding" on the back of my eyes with some displays and all of them have a very high frequency. There is no pounding on my phone/TV/tablet/steam deck. There is strain, but not in the back of my eye.