Help!!!My goldfish eye is purple and bulging!!!?

well how long have you had your goldfish? if hes old ( in goldfishy old-ness) maybe thats just showing a sign of old fishy age. and an other reason could be well if he lost his eye the other time maybe this algea cleaner is just ruining his eyesight like a well fishy birth defect. lol but i havea feeling hes gonna be fine. good luck!