I get enough questions about a fish with cloudy eye(s) that it's worth a sticky I will refer to. Beats having to write it out each time I get the inquiry.

One Cloudy Eye

The single cloudy eye can be due to a (A) bacterial infection (highest probability), an (B) injury (next likely cause), a (C) viral infection (least likely), or the onset of (C) another disease (likelihood mixed in there -- somewhere).

Just because you have other fishes that don't have one or more cloudy eyes, DO NOT draw any conclusions from this. Fish are suseptible to bacterial, viral, and disease at different 'levels' of resistance. So, just because the fish has one cloudy eye, and there are more than one fish in the system and the others don't have a cloudy eye(s), doesn't mean it HAS to be an injury.


(A) If it's a mild infection with just one cloudy eye, you need to do two things:
(1) Improve the fish's diet. Just because the fish is eating a lot of food doesn't mean it's getting the right nutrition. If you don't know what the fish should be eating, now is the time to do the research. Read the sticky in this Forum on Fish Nutrition AND the one on Fish Food Forms. Add vitamin and fat supplements to the the fish's food (see above link).

(2) IN ADDITION TO THE ABOVE, you need to look over your system and reduce the number of bacteria in the water. Check your skimmer. Use carbon filters to filter out what the skimmer can't remove. Are these two things being maintained properly? Remove uneaten food, dead things, and detritus from wherever it gathers in your system. Remember to clean out all filters that collect solids, and maintain them properly. Review your water change and maintenance activities. They may not be sufficient or being done properly. Clean out filters that catch solids. Maintain them. Watch water quality.


(B) If it's an injury, the cloudy eye may not be uniformly cloudy. It may have a scratch/damage on or near the eye somewhere. You may not be able to see the scratch/damage easily. Treat this like the fish has a mild bacterial infection (see above and follow BOTH (1) and (2)). The fish should heal it on its own.


(C) It maybe the onset of another disease. Many parasites and diseases have the cloudy eye symptom. Treat the fish as if it had a bacterial infection (see above), but be on the lookout for any other disease or parasitic infection signs. If it's viral, there is nothing more to be done other than the same as for a bacterial infection.


Two Cloudy Eyes

With two cloudy eyes, (B) injury is unlikely. The fish most likely has a (A) bacterial infection. Move the fish to a QT and treat with an antibiotic. Improve the fish's diet (see (1)). I would suggest Nitrofurazone. Just follow directions on the medication. Don't return the fish to the DT until the eyes are clear. Fish that have been ill from another disease or condition often get a bacterial infection as a secondary illness. Treat them as indicated in this section.

If the diet isn't proper, you can choose to move the fish to the QT and inprove its diet AND treat with an antibiotic or just keep the fish in the DT and improve its diet. From my perspective, most hobbyists don't feed their fish properly, so moving to the QT, looking into improving diet, adding vitamin and fat supplements to its food, and giving an antibiotic treatment is the best approach. In a QT the fish can more easily targeted for feeding AND you only want to use an antibiotic on a fish in quarantine. Use an antibiotic that is for 'topical' (surface) infections. One of the best is Nitrofurazone (found in the product Furan-2). Look for this ingredient in the antibiotic you have available.

In either/both of the above cases (i.e., either one or two cloudy eyes), you still want to look over your system. Follow what is in (2). Returning a healed fish back into a sub-standard environment is not going to keep the fish from getting re-infected.


(C) This could be a sign of an oncoming disease. Like before, watch for other symptoms, but proceed to treat as if it is bacterial in nature. If it's a virus, treat as if it is a bacterial infection.

Open up a new thread and post photos of your fish, showing the eye up close, if you are unsure. Hope this helps!