KM Yes, I forgot to mention PWM.
But the issue here is that people are not sure what is their problem and when discussing with manufacturers, it is all over the place and they get the feeling that we are just a bit out of whack.
I still maintain, that I swear that if there is a non-flickering LED light, be it blue, white, what ever, anyone can stare at it for quite long, provided it is not to bright to hurt, without symptoms. So if the backlight of a LCD display is White led and it really does not flicker, I mean not even 100Khz, then it will not cause any discomfort to just stare at the light.
UNLESSS, the person has some problems in the daylight staring at a blue sky.
This is my very strong hypothesis, I might be proven wrong, but I have seen zero evidence that it would be the case.
I've been sensitive to PWM now for 30+ years but I just did extensive remodeling at my summer cottage using a LED light that flickered at 100Hz. I had zero discomfort though I might work for 10 hours under that flickering led light.
But I get bloodshot eyes in 15 minutes from an OLED or backlight 240-2500Hz flicker or temporal dithering.
If we could just contact Intel and tell "Hey, we have a large group of people who are able to use Lenovo x280 without any symptoms, internal screen and external screen, but unable to use any more recent like L13 with Internal nor external. "
I think they SHOULD be able to know what is different in the display adapter characteristics and make another display adapter for future computers that would have the same characteristics as the x280.
But those discussion always digress to some multiple issues and then the manufacturers think that these people are a bit crazy and we cannot help them.