My son's halloween costume came without Harry's glasses. I couldn't believe it!
I designed some that will fit nicely on his face. They are small and designed to fit a 5 year old.
update 10/18/14. I just realized I'd never uploaded a photo of how they fit... just fixed that.

Print out all three pieces and connect the temples to the frames. You can use twist ties to hold them together or small bolts will work too.
Unfortunately the hinges are not live, so don't play too hard. Maybe somebody with more time can do a hinged version.