Some random hardware impressions:
The only display I can currently use for extended periods is an old Dell CCFL-backlit monitor that I bought second-hand (which uses PWM at non-full brightness) that is hooked up to an NVIDIA graphics card (not sure if that has anything to do with its tolerability). Even so the monitor doesn't give me eye strain at non-full brightness. An HP ZR2740w (which doesn't use PWM) hooked up to the same graphics card gives me eyestrain fairly quickly.
My phone, an Xperia ZL, gives me eye pain with even a glance. (I know some people might find that suspicious).
My laptop, a Dell E7450 doesn't have PWM but has annoying temporal dithering. (I assume from the Intel graphics). The screen feels relatively non-abrasive to the eyes and I can use it for a low to moderate period of time, but not as much as my primary display.
PWM tested from http://www.testufo.com/#test=blurtrail