Fish eyes water. As a result its a common condition in new tanks. Sometimes however cloudy and swollen eyes can indicate popeye disease in your aquarium fish. Just because a fish has bulging eyes doesnt mean theres a problem. This mean that the water is around 160 degrees making it perfect for some really delicate green teas such as japanese senchas and gyokuros.
It is the point where you first start seeing bubbles in the water. Treatment with a good antibiotic should cure these infections. High nitrates nitrites ammonia metal or plastic poisoning can be the reason too. Silicone is a synthetic material made from silicon similar to sand oxygen carbon and hydrogen.
Some fish breedslike the black moor goldfish and the celestial eye goldfishare prized for their large telescoping eyes which are perfectly normal and healthy. They are small quasi circular areas of substrate that are exposed through the applied coating immediately after application and which have at their center a source of contamination. Fish eyes are similar to the eyes of terrestrial vertebrates like birds and mammals but have a more spherical lens. They have eyes raised above the top of the head and divided in two different parts so that they can see below and above the water surface at the same time.
Fish eyes contain many of the same components as human eyes but they are structured and used differently. The four eyed fishes are a genus anableps of fishes in the family anablepidae. Poor water quality often leads to cloudy eyes in fish either directly or indirectly usually due to a weakened immune system. Fish eye is almost always caused by silicone that has managed to get into the wood for example through a crack in the finish.
Another is the onset of cataracts in fish. If its one eye chances are its injury if its both then it is possibly a bacterial infection. Internal parasites such as protozoa or flukes are one cause. Because poor water quality can be caused by any number of reasons there are a few steps you need to take to lessen cloudy eye symptoms.
Unsuitable salinity can also be the cause. Bacteria can infect fish eyes damaged by injury. Like their relatives the onesided livebearers four eyed fishes only mate on one side. Im not aware of any treatments for those problems.
Fish have a cornea or outer covering a lens for taking a picture an iris for adjusting light a retina containing light sensitive cells and an optic nerve for translating the picture to the brain. Shrimp eyes are how the tiny pinhead sized bubbles are described. Bad water quality is a common reason enough to be the cause. Birds and mammals including humans normally adjust focus by changing the shape of their lens but fish normally adjust focus by moving the lens closer to or further from the retina.