Originally Posted by CallsignVega
Uh ya. I had many 2B Catleaps (1440P overclockable IPS), and they had really low PWM frequency. It got so bad I had to run them at 100% brightness and turn down the brightness setting in the GPu control panel. Ended up selling them as they were too rough on my eyes. I only buy DC control monitors now. It's funny though, strobing backlights don't affect me, but PWM does. Not exactly sure why, but Mark would be able to expound on that maybe a little better.
Multiple strobes per refresh cause an ugly-motion phenomenon:
(From LCD Motion Artifacts 101
For certain people, this PWM artifact
sometimes is a bigger cause of eyestrain for some people, than the PWM flicker
This is like the 30fps@60Hz double-image artifact (CRT/plasma).
180Hz PWM @ 60Hz refresh, or 360Hz PWM @ 120Hz refresh, creates a triple-image artifact (Low-frequency PWM dimming).
If your monitor has PWM dimming, do this:
1. View animation at www.testufo.com/ghosting
2. Gradually adjust brightness from 100% down to 0%.
3. You will witness motion gradually become uglier and uglier, the lower brightness becomes.
4. That's the PWM motion artifact you are seeing. Motion-optimized strobe backlights do not do this.
5. This artifact creates eyestrain for several people (including me and CallSignVega).
Motion blur and motion artifacts makes it feel like we're perpetually seeing an unfocussed image, or perpetually seeing double-images. This strains our human brain and/or eye focussing muscles, since the rough image motion artifacts gives an unusually aggressive workout. This is why it increases eyestrain when our eyes are unable to focus on moving objects that have forced artifacts (unavoidable display motion blur or unavoidable PWM artifacts). Only CRT's and strobe-backlight monitors can cure this specific type of eyestrain if you're not sensitive to flicker.
Thusly, PWM's flicker is NOT
necessarily the cause of eyestrain for everybody. It can be, but this is a different kind of problem that PWM does. Assuming you don't have other sensitivites (e.g. LED color spectrum issues, etc) this behavior often explains people who don't have CRT eyestrain and don't have LightBoost eyestrain, but ends up having PWM eyestrain during long periods of videogaming. For a person whose eyes loved CRT and hated PWM, then such people should try out a strobe-backlight computer monitor (e.g. LightBoost, Turbo240, etc).Edited by mdrejhon - 11/10/13 at 11:15am