First off, take a deep breath. Relax. IF the eyecap didn't come off with the shed, it's not going to hurt the snake. Chances are, it'll rub it off itself within a couple of days. If not, it'll come off with the next shed. If it's not a stuck eyecap, then maybe the snake just bumped its eye on something during the shed process. It'll sort itself out in time. Just make sure your humidity levels say around 50% and the snake has plenty of fresh water available every day...and it'll be fine.