Thelaziasis
![Thelazia callipaeda infestation in a dog.[1]](/uploads/202502/15/Thelazia_callipaeda_in_dog5135.gif)
Thelaziasis (occasionally spelled "thelaziosis") is the term for infestation with parasitic nematodes of the genus Thelazia. The adults of all Thelazia species discovered so far inhabit the eyes and associated tissues (such as eyelids, tear ducts, etc.) of various mammal and bird hosts, including humans. Thelazia nematodes are often referred to as "eyeworms."