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Prevent pop-eye from afflicting your fish, and learn how to deal with the condition if it occurs in your tank.

By Stephen G. Noble |

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Exophthalmia (pop-eye) is a gruesome affliction where one (unilateral) or both (bilateral) eyes of a fish abnormally protrude from the eye socket. The common name "pop-eye” was coined by hobbyists in an attempt to differentiate this from other tropical fish eye ailments, such as corneal opacity. Exophthalmia often results in permanent disfiguration or death.

Other than a protruding eye, fish with pop-eye may or may not display other signs of illness. One fish with a swollen eye can easily be overlooked if the fish is a member of a large school. In other situations, the fish swims wildly or loses buoyancy drawing attention to its suffering.

Even the scientific community is uncertain of all causes of exophthalmia. But in the aquarium there seems to be a direct correlation between exophthalmia and eye trauma. Corneal abrasions can cause eyeball swelling. Probably the most common cause of exophthalmia is poor water quality, which lowers a fish’s resistance to disease, inviting pathogenic conditions, such as ocular tumors and staph infections.

Want to read the full story? Pick up the December 2010 issue of Aquarium Fish International today.

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