Has anyone tried reading stuff on their iPhone X in near or total darkness? I was reading this forum - the brightness on the phone was of course set very low, probably on lowest - and holy crap does it ever cause crazy amount of eye strain! I thought I was either super tired, or my eyes were going bad - it was getting almost impossible to focus, after a few minutes, and I tried squinting, trying to see anything clearly. Eventually I just gave up. Next night, same exact thing, and I was confident I wasn't tired, and that my eyes weren't tired at all.
Reading about it today, and it actually seems to be a pretty common problem. It's most likely due to screen PWM (240Hz full screen on/off flicker) that practically all OLED screens on phones use. Thankfully, LG OLED TVs do not use this technology (never had this kind of problem while watching my TV) but instead use the voltage based brightness control. Due to this, TVs have more problems with color uniformity - but no flicker. Tonight, I'm going to try the test with regular old iphone 6, which uses LCD screen with no PWM flicker, and see for sure if I'm going crazy, or if X just shouldn't be used on low brightness in the darkness :\
Actually, reading even more about it, there's a 60Hz screen flicker even with high brighness on X, but it's not a full on/off type of flicker, but rather a smaller flickering brightness variation. This is something I don't think I can really notice, but I'm not going to lie, I don't like that it's there, as it probably tires eyes out more than it would if there was no flicker.
Here's the measuring of the 60Hz (100-50% brightness) and PWM (50%-Min) brightness:
https://www.youtube.com/watch?v=DXOdaFwdKlY
Here's a video that clearly shows that 60Hz pulsing exists on high brightness, by recording it with a 240FPS camera and playing back in slow motion:
https://youtu.be/99w3Wmp1agI?t=2m25s
