The infection of parasites causes all kinds of parasitosis. The parasites that causes ophthalmic diseases are Protozoa, Nematodes, Cestodes and so on. These parasites has specific connection chains in between parasite and vector, parasite and host, host and host. If these connection chains were polluted or exposed into the worsened environments, the parasite are infected into human body which is its host. The parasite causes the destroy of organic tissues or inflammation and allergic responses by its toxicity and resistance of the host. In worst case, it might cause blindness. In order to prevent these disease, we should keep the clean and clear living environment of every human being.