This Clown isn't in the 75g, is it? If so, I would consider either rehoming it or getting a much larger tank. They get over a foot and a half long. The size it is now does not matter so much...as with Angels and Tangs that are in "too small" tanks, it will stress and not thrive. This is likely just the start of the problems if you keep it..
Cloudy eyes are usually a water quality issue. What are your parameters? How often are you doing water changes?