I've known some people who wear glasses just to look cool, and others who wear it for a costume.
However, some asking "Why do you wear glasses?" on a hot, sunny day, with the person being asked wearing sunglasses, then you can consider that dumb.
*yanks my glasses off*
How many fingers am I holding up?
This. That kind of thing made me laugh the first 5 times, then annoyed more for 2 more times, and then for the next hundred times I have just make sarcastic jokes "Huh? Where'd you go?" and random stuff like that.
My eyesight isn't that bad without my glasses, I can function fine, but I can't read the small prints that teachers often use on boards and other things like that.