Even when there is no risk of any sunglare. Was it Ray Charles who started the trend ?

Either to hide there stoned eyes or the flashes from the camaras

Strictly fashion, I believe, or maybe they actually think that wearing sunglasses hides who they are, but really just think it is fashion statement, if you notice the styles of the sunglasses are like clothing they change from season to season. I don't think Ray Charles started the trend he wore them because of being blind and the sunglasses help take the attention away from his eyes