Don't worry its not that rare. It's a build up of bacteria. Simply wet a que-tip and gently massage is out of his eye. You're going to have to restraint him so be prepared of your little man hating you (even more if thats the case) lol. After you get the jelly fish looking thingy out of his eye, give him a long shower. If you don't have one of those expensive misters you could always buy an auto-mister and tape the trigger to shoot and have it pointing towards the top of whatever plant you have set-up in his enclosure. Shitty thing is, you're going to have to re-fill it a number of times before the day is gone. Good luck
-Brian