iPhone 4/4s, HTC One M8, Windows 7/LTSB 2015, specific NVIDIA graphics cards, almost all AMD cards, Firefox Quantum, Android 7+, PS3/4, Wii, Xbox, Amazon sticks, OLED/Plasma TVs all have multiple reports of being usable/unusable. Maybe even more. The number of reports is the closest thing that defines usable. I believe we should start a wiki right now and everyone who feels like it adds his experience of ehat works and what not in a detailed way. New members arrive and have no clue where to start. A wiki would help a lot. Basic things like "stay away from OS/app X, Y, and Z." "Avoid graphics card No. 97x." "Test if you are sensitive to blue light or PWM with exactly these tools". There are patterns that can not be denied. Back then I did believe the members in the Apple forum's Macbook Pro eye strain thread who basically said "keep buying iPhone 4 until you get a usable one". And I kept buying and it worked out. It helped. That was some years ago. We have a lot more info now. Our information can help people who are new and do not known where to start. This condition can appear overnight, and then you are clueless and have to act. In this case a wiki that says "this and that works for user X, Y, Z" will help most certainly.