Please explain the following:
If I use my Dell monitor in landscape mode I am OK. If I use the monitor for a few hours in portrait mode, my eyes will have something like scanlines for a few hours.
My eyes are pretty much OK and I don't wear glasses. This is not a medical question but rather:
How this is possible, technically speaking? Does a monitor got a different horizontal refresh rate and a different vertical refresh rate? Also the monitor I use doesn't use PWM.