Will try to watch this tomorrow, but judging by the comments, it seems very interesting haha. I think it damages your eyesight depending upon brightness, and duration etc.. Mainly why people take breaks, and wear sunglasses outside.
I've never played first person shooters and most likely never will. I also don't have any viewing disorders. One of my pupils is bigger than the other but it doesn't affect my view of sight at all.
According to my doctor my eyes are like 1 in 10k people or something I forgot the term but apparently its rare form of eyesight XD