Pronunciation: [θɛlˈe͡ɪzi͡ə] (IPA) 
The spelling of the word "Thelazia" is quite unique and may pose a challenge to spellers who are unfamiliar with it. The word is pronounced as /θəˈleɪziə/ and refers to a genus of parasitic worms. The first syllable "the" is pronounced as "thuh" and the second syllable "lazia" is pronounced as "lay-zee-uh" with the stress on the second syllable. The word is derived from the Greek word "thēlazein" which means "to suckle".
Thelazia is a genus of parasitic nematodes that primarily infect the eyes of animals, including humans. These roundworms belong to the family Thelaziidae and are commonly known as eyeworms.
In terms of morphology, Thelazia worms have elongated, slender bodies, typically measuring a few centimeters in length. They are characterized by their anterior end, which features a buccal capsule with three lips and two tooth-like structures. This enables them to attach to the eye tissues of their host.
Thelazia nematodes have a complex life cycle. The adult female worms release microfilariae into the conjunctival sac, which are then ingested by different species of flies, such as Musca, that act as intermediate hosts. Inside the fly, the microfilariae develop into infective larvae, which are subsequently transmitted to a new host when the fly feeds on its blood or tears.
Infections caused by Thelazia species can result in a variety of ocular symptoms, including conjunctivitis, lacrimation (excessive tearing), keratitis (inflammation of the cornea), and even blindness in severe cases. These infections are usually diagnosed through direct observation of the worms in the eye.
Thelazia infestations have been reported in different regions worldwide, primarily affecting domestic and wild animals. However, there have been rare cases of human infections as well, often associated with close contact with infected animals or exposure to infected flies.
Effective treatment options for Thelazia infections involve the removal of adult worms from the eye through mechanical means or the use of antiparasitic medications. Preventive measures include good hygiene practices and avoiding contact with flies and potentially infected animals.
The word "Thelazia" has its etymology rooted in Greek. It comes from the Greek word "thēlē" (θήλη), meaning "nipple", and the Greek word "thelazo" (θηλάζω), meaning "to suckle" or "to nurse". The term "Thelazia" is commonly used as a genus name for parasitic nematodes that primarily infest the eyes and associated tissues of animals.
