Agreed with quarry but I wouldn't move to a QT
as yet. These types of problems are often easily dealt with. Eye problems are usually caused from some sort of trauma to the eye and made worse by water quality. Not to suggest your water is not good, just there may be enough DOC
to feed the bacteria making it harder for the fish to fight it off itself.
Do several water changes over the next week with well aged SW
and feed with vitamin foods high in [acronym="Highly Unsaturated Fatty Acid"]HUFA
[/acronym]. You can also add 1 tablespoon of epsom salts per 50 gal
of tank water. The Magnesium will help with any eye swelling. If you do not have an Mg
test, do not add more than once a week. The water changes should add a decent amount as well.