Sunspark I was watching a video earlier today of a proof of concept attack on a Dell monitor where they were able to get it to draw some stuff on-screen to make it look like everything was fine when it wasn't. Pretty interesting.
Think I've seen the study behind that, have not seen the video though.
Some people claim minor voltage fluctuations can caused flicker of what is otherwise a backlight not using PWM, so it is true issues with power supplies or analog driver circuitry could contribute to eyestrain.
In addition it depends on the device but there can be some integration between the co-processor(s) driving the panel and any additional "smart" functionality bolted onto the unit. @KM has discussed this in depth with a particular model of Sony TV and its issues.
Sunspark it can also be what's in the monitor itself driving it which is interesting to contemplate because many here have identified a certain date as to when things became more problematic
Someone on another forum claimed to have a Dell monitor that caused eyestrain and tried an Eizo monitor that supposedly had the same panel and claimed that was better. If it really was the same model of panel I think it could either be the driver circuitry or perhaps Eizo has stricter QC standards compared to other manufactures.