I have a 20 gallon tank, running for about 5 months now...with 3 relatively small fish (the biggest is 3 inches tip-to-tip). I'm currently treating them with Parasite Clear to rid them of flukes...which I think they are all infected with. Anyways, they don't appear to be getting much better, but I'm not ready to give up. The water quality is perfect (0,0,5) and I just did a 30% water change tonight and gave them a third dose of the the Parasite Clear. I have an UGF and a HOB filter and an airbar. I treat the water before adding it.
Anyways, my question is apart from all that. My black moore seems to have one swollen eye....and I can't tell if it's just bigger then the other one, or actually popping out...I have a feeling though that this isn't a normal looking eye. It sort of has a bulging ring around the base of the one eye...the other eye looks fine though. I did some research and basically all I could find was that if it's not in both eyes, then it's probably not popeye...and if it's in one eye, then it might just be from an injury.
Any thoughts? What's causing this? His eye also has a little red speck in it, that I noticed a little while ago. I also feel like maybe the eye's been like this longer then I think, as I had noticed his eyes getting bigger, but had somehow not noticed that one of them wasn't really growing at all...hm, strange....
anyways, thanks for the advice!

Does it look like this?

It's hard to tell, cause he's a black moore...and therefore his eye sticks out anyways. I think it does though....except there's no discolouration, it's still black around the eye.

Is it like this one?

Hm...it's so hard to tell. It's not lighter in colour around the eye, though I don't know if that will come with time. The eye definitely bulges around the base of it, but I really can't tell if it's supposed to be like this or not. It doesn't look like the other pictures of the telescopes on the page (up top and over at the left)......
What types of things cause eyes to swell? Should I be worried, or is it safe just to leave it for now (at least until I can get this flukes thing under control)?

Well mostly bacterial infections or water increasing in the fish causing the water retention in the eyes.

You could just try raising the temp to 78-80F and add some Epsom salt 1/8 teaspoon per 5 gals of water. This might help decrease the swelling.\:D

Is it correct then to assume that because the swelling is in one eye only, and because it's not discoloured, that it's not popeye or anything too serious? It definitely is swollen, that I have determined....though I can't tell if it's worse, the same or any better.
I'm currently treating the tank with Parasite Clear due to a possible fluke infestation...but once I'm done the treatment I will try the salt....is that all I should do then?