Actually, all of his senses are "super." Senses other than sight and hearing don't come up too often, but they are all super-sensitive. It's never quite explained what this means in terms of invulnerability, but the best version I heard was along the lines of "Sure, the bullets bounce off, but that doesn't mean I don't feel them when they do."
So, yeah, almost certainly feel a spec of dust or something. Of course, there's the question of
how he'd feel it. If his body is invulnerable, than something like that wouldn't be doing any damage. So, while he'd know that it's there, he probably wouldn't find it
painful. (Same goes for the bullets, actually.) It probably could get pretty irritating after a while, though.
Oh, and incidentally, I now get to do one of my favorite things as a boards moderator. See, this is a question about Superman. Therefore, it is actually on topic. So, I'm going to move it to a different forum.
Paul
