I think the glasses issue is strictly tradition because Siegal and Shuster wrote it that way.
There are many other ways he could hide his identity. I'm not buying it that glasses is the only thing that protects his identity.
He acts differently as Superman. His pose is different. His hairstyle is different. Then of course in some of the comics - 60's and maybe the 70's, he used a type of hypnotism and everyone actually thought Clark looked totally different. Also, everytime he was Superman, he quickly vibrated his head so that all pics / film of him was blurred. (Yes, I know the Flash is supposed to do this, too, but I have the comic where Supes does the exact same thing.)
Of course, too, as Martha says, "They don't call him tights for nothin'."
I like that in NanSmith's Home series, he has completely gotten rid of the glasses and no one recognizes him.
There is some Superman canon - I assume from the comics - that he started wearing the glasses to help him control his special vision abilities. I know I've read that the lenses are leaded glass. Perhaps he started using them because he saw something he wished he hadn't?
And if Clark went without glasses, what would he say when someone noted that he looked a lot like Superman? Coincidence. A lot of people look similar. Otherwise, how would we have all those celebrity impersonators?
Then too, I've seen pictures of people that I would not have recognized as that person unless I was told it was them. Surely that's happened to the rest of you. There is even a picture that's maybe me, but no one can decide for sure (and I was an adult) - including my own mother. Now isnt' that a hoot?
