For a long time I dismissed temporal dithering or other pixel dithering as my issue. I dismissed it because:
The Asus VS247H-P monitor from 2013 that I can use all day without an issue is 6 bit + FRC = uses temporal dithering. It also uses PWM. (I’ve tested and confirmed the PWM but technically haven’t test-confirmed the TD.)
I have experienced discomfort with an offending monitor when it is on with black screen/ no signal to monitor, but backlight on.
I have experienced the same symptoms from an LED desk lamp!
This led me to believe the LEDs themselves were somehow causing my eye strain.
However, I am now reconsidering temporal dithering or other flicker as being the primary cause due to the following:
I tried the BenQ TK700STi DLP projector that uses a lamp (not LED!), and it definitely triggered the symptoms. It uses pixel shifting/ flickering (at 240 Hz) to achieve 4K resolution. Also as a DLP projector, I could also easily see the flashing red/ green/ blue “ghosts” of white objects as I moved my eyes quickly.
In offending monitors I’ve always noticed two subjective observations about the color:
I’ve noticed that the colors just look “not solid” to me. No matter how I tweak the color settings, I can’t get them to feel “solid.” (Meanwhile my 2013 Asus VS247H-P 6 bit + FRC monitor does NOT feel like this to me; the colors feel solid.)
No matter how I tweak the color settings in the offending monitors, the discomfort persists: however, the “quality” of the feeling/ discomfort does change with color settings change. This implies to me that the monitor may be implementing different dithering with the color settings changes.
Has temporal dithering changed over time? Is there some other kind of flicker present in almost all modern monitors and TVs, that is not present in most phones and handheld devices?
Just thinking out loud in case anyone has any input. I very much appreciate all ideas!