superman xray vision
So how does Superman do it! He can see through buildings and clothing (he checks out Lois Lane's underwear in Superman 1 - more on this later). Many have attempted to answer this question of the ages yet few have explored this in as much depth as J.B. Pittenger who published a study in the journal Perception back in the stone ages (1983) entitled "On the plausibility of superman's x-ray vision"
But first, before we get into the meat of the paper, lets see what others around the InterWebs have said about Superman's amazing seeing through underwear powers.
In Correcting Misconceptions…