Don't give up on them! I had a really similar thing happen to my tank a while back, right down to it involving a juruense catfish. Keep up on the clean water and melafix is up to you. Depending on how long they've been that way, you should be able to save their sight. Even if they do end up blind in one eye they can still go on pretty well. A couple of mine ended up losing sight in one eye, but they're doing fine now, even occasionally act like they want to breed. Sorry for you loss thus far but I believe you can save the rest.
