My opinion about cloudy eye(s):
A single cloudy eye could be the onset of a debilitating disease, or parasitic attack (e.g.,
Cryptocaryon irritans), an indication of poor water quality (ammonia), or nothing. On the ââ"šÂ¬Ã‹Å“nothingââ"šÂ¬Ã¢"žÂ¢ side, it could be, like you wrote, the fish injured the eye in a mild fight with a tankmate, net damage, ran into some decoration in the tank, or managed to pick up a mild bacterial infection.
All of these ââ"šÂ¬Ã…"œone-cloudy-eyeââ"šÂ¬Ã‚ situations are ââ"šÂ¬Ã‹Å“probablyââ"šÂ¬Ã¢"žÂ¢ not worth taking any specific action as far as the fish is concerned. The fish should be closely watched for whether the eye is healing or getting worse. The fish should also be watched for any other symptoms of disease. But, there are things to do and think about as far as your tank and water quality is concerned:
Check all water quality parameters. Monitor ammonia especially an hour after feeding. If water quality is eliminated for sure, then make sure there is no decaying matter in your system to address a possible bacterial issue. Time to do a thorough cleanup. This can reduce the numbers of bacteria in the water column. In addition to checking ââ"šÂ¬Ã‹Å“the usual suspectsââ"šÂ¬Ã¢"žÂ¢ with regard to water quality, also check for dissolved organics. Be sure your fish is receiving proper nutrition/diet/foods in adequate quantities, and isnââ"šÂ¬Ã¢"žÂ¢t under stress (tank too small, issues with tankmates, water quality, etc., etc.). Regarding nutrition, are you sure you are feeding the kinds of foods the fish
should be eating? Are you using vitamin supplements? using a fat supplement? and adding some beta glucan to its food during this time is a good idea.
You want to have a treatment tank/quarantine tank standing by, and in case things get worse, youââ"šÂ¬Ã¢"žÂ¢ll need to put the fish into quarantine. A great, comprehensive guide on quarantine tanks and procedures can be found in this article:
http://reefkeeping.com/issues/2004-10/sp/feature/index.htm
If the eye is cloudy AND there is obvious swelling, then besides a bacterial issue, it could also be a parasite. I think the fish should be treated for a bacterial infection, like if both eyes were cloudy (see below). This is assuming there are no other signs of any other disease or condition. If a parasite is suspected, a fresh water dip might knock it off. In your case you say there is what appears to be a bubble. We would need to see a photo of it, up close. Might it be a parasite?
If your fish has
two cloudy eyes, then this is something to be more concerned about, IMHO. Itââ"šÂ¬Ã¢"žÂ¢s not likely it ran into something twice, on each side, or hurt itself symmetrically. The suspicion of disease now goes high. If you can see no other symptoms of disease, the fish with two cloudy eyes should be moved to a treatment tank and treated with an antibiotic, IMHO.
A fish with two cloudy eyes from a bacterial infection shows there is something ââ"šÂ¬Ã‹Å“offââ"šÂ¬Ã¢"žÂ¢ for sure. There is always bacteria in our tanks, but healthy fish keep it at bay. And in a healthy tank, the bacterial population in the water column, isnââ"šÂ¬Ã¢"žÂ¢t high. When a fish gets a cloudy eye or eyes from bacteria, then something has interfered with the fishââ"šÂ¬Ã¢"žÂ¢s ability to ward it off. Too many bacteria (decaying matter, overfeeding, dead fish, dead snail or crab hidden away), a poor diet, ongoing stress (tank too small, tankmate issues, water quality) ââ"šÂ¬Ã¢â‚¬Â something that is letting the bacteria get by your fishââ"šÂ¬Ã¢"žÂ¢s normal defenses ââ"šÂ¬Ã¢â‚¬Â are possible causes. Look into these matters and make corrections. Check your water quality closely (keeping in mind that you cannot test for everything, so something could be wrong that youââ"šÂ¬Ã¢"žÂ¢re not even testing for. For this, you have to play detective.) Make sure you also check for dissolved organics. Is your fish getting the right kinds of foods that it needs? Same as mentioned above. . .vitamins, fats, and at this time, beta glucan.
