How are his appetite and energy levels? I don't see any blistering or swelling. Honestly, it looks like rub marks. I'm going to take a wild guess here and say that he was in a 12x12" glass square when you purchased him. It looks like he spent time pacing the front of the enclosure putting pressure on the raised areas around his eye. I would at least have a fecal done to make sure there is no parasitic involvement. If he gets bad, or is bad, do as brownie64 said, contact Petsmart and let a vet check him out on their dime.