Reported throughout North America, this condition affects the eyes of the fish. The infection, caused by various trematode or protozoal parasites, invade the skin of the fish, after developing in aquatic snails. The Diplostomum parasite larvae migrate throughout the fish but can develop into the next maturation stage in the lens of the eye. The infected fish must be eaten by a type of bird to complete the parasite's life cycle to adult trematodes in birds. Myxosoma scleropercae is a protozoan parasite that commonly invades the eye of the perch. The formation of microscopic cysts in the eye's surface causes impaired vision of fish. Other conditions can also cause a whitening of the eye's corneal surface. After death, eyes also become cloudy.
Human Safety: There is no known danger to humans who consume fish with these parasites in the eye. The poor condition of fish which are blinded by this parasite make them unsuitable for consumption.
Pop-Eye - See Gas Bubble Disease
