Welcome to the group. Eye infections can sometimes be a real tough battle.
First step would be to give the fish a bath in methylene blue. This helps as an antiseptic and helps the fish's immune system to get some extra oxygen into it to battle the infection.
Next dosing in a bath with erythromycin (aka Maracyn at 2X the recommended dose usually works well with the gram positive bacteria associated with eye infections. This treatment will need to be done over 10-14 days as fish are usually very slow to respond to the help of antibiotics.
Last step, if necessary, for stubborn eye infections, to help prevent permanent damage to the eyes is to treat the fish's eyes directly with a Silver Nitrate solution. See below.
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