I got a powder blue tang 3 and a half weeks ago from my lfs, they informed me that a customer brought it in because he was tearing down his tank. He looked nice and healthy so i picked him up. Upon bringing him home and inspecting him in QT i noticed one eye was super damaged looking, cloudy, almost no iris, a little different shape even, i was sure i didnt see that at the store but maybe i only saw one side of him the whole time. I did a 5 min RO dip to check for flukes and saw nothing, then dosed seachems paragaurd in the 5 gallon QT and let him stew for an hour. There seemed to be no side effects and the eye was the same so i put him in the tank and hes been happy ever since. BUT his eye is still really bad looking, first off im hoping it is not a parasite that is slow to show symptoms and the paragaurd didnt have time to work on because i have many other fish in the 120 with him. And also im wondering if he could lose his eye and what i would have to do about it! But like i said ive had him for 3 and a half weeks and it may have gotten a little bit worse but the rest of him is healthy looking as are all the rest of the fish. Thank you