Help with my glass fish who has left sided popeye and a white, bumpy patch?

I have a 29 gallon tank that has been up and running for about 4 years. The last 2 years have been excellent, with only 1 fish lost. I have a glass fish that has been in the tank for about a year. Two days ago, I noticed it has a popeye on the left. On the same side of his body near the tail there is a patch of white, raised bumps about half the size of the pencil eraser. There is a pink area sitting just under the white bumps. (It looks almost like a tiny cluster of white grapes). There are no other spots on his body.

I treated the tank with Tank Buddies for bacterial infections, and it didn’t seem to do any good. He is eating fine, and otherwise acting normal. And he can’t be too bad yet because the catfish hasn’t eaten him. (The catfish tends to dispose of weak fish).

Any ideas on what this might be and what I can do about it?