Originally posted by ReefyMark
is it only one eye? IME, popeye has afected both eyes.
It can affect one eye or both eyes.
Tselios - The first thing you can do is to post some water paramiters. Also tell us about your tank and other fishmates. Is this fish getting picked on in any way, showing any odd behavior?
If it is popeye then you need to start a good, aged, water change of about 30%.
If it is truly infected then you need to have a QT tank ready.