Our 4 month old Easter Egger is keeping her left eye shut. If she hears a loud noise she opens it but then closes it again. She is hanging back from the other chickens and her feather seem a little messy. Any ideas? No goop or anything around her eye. What should I look for? I worry because we had a 3 day old EE from the same hatching die and it started with closing it's left eye and progressed to limping and not eating.