Allekss
The vast majority of monitorbrand, including OLED, IPS, VA, TN uses PVM. Meaning the higher brightness the higher/faster pulse and less flicker.
But as soon as you adjust the brightness to lower levels or applaying e.g. eco view, meaning the monitors sensor recognizes lower ambient light and therefore lowers brightness, the pulse gets lower and flickers starts to occur.
My collegues dad that has severe issues after a stroke, has tried a lot of monitors. The only brand he can sit in front of is EIZO.
They seem to have a hybrid techique.