Dark-tinted glasses, worn for a variety of reasons.
1: If it's a bright day.
2: If you have been given a
black eye and want to
conceal it.
3: You are making a (not-very-good) attempt to conceal your identity.
4: You are a
complete tit who thinks wearing sunglasses makes you look like a gangster or a pop star or something.
"Why does
Sunglasses Roy wear shades even when it's dark? Does he think it's cool?"
"Er, no. He's actually an alien with
red eyes and doesn't want anyone to see them".