Are the eyes swollen or just cloudy? If they are swollen, then I would concur that it's popeye, which is a bacterial infection.
If it's just cloudy, like a cataract on it, I'd suggest a FW dip. It could be trematodes, parasites that attach to eyes and gills. We've been seeing a lot of it lately, from various suppliers, and while mostly tangs and angels get it, any fish can.
5 min FW dip (as I've described in a couple of other posts along this vein this morning) should kill them and they will fall off, looking like clear or white sesame seeds.
I'd try that before medicating. It's a short 5 minutes of stress compared to the stress of medicating, etc.
HTH
Jenn