Good temp, but you might want to up your changes per week.
If it's not filtered, try out 1 50% and 1 100% weekly to see if overall health condition improves any. This boy may just be a little more sensitive to water quality than others are. It happens.
Cloudy eye is usually a sign of water quality issue if it isn't a very serious case (In my experience at least). Slight clouding might mean the water is more than they can handle or there is something irritating in the water.
Clean, warm water, good food, and maybe some Epsom salt is your best bet for the swelling and cloudiness, in my opinion.