Cysticercus cellulosae (the scolex of taenia solium) is not very uncommon in the eye. Its usual seat is beneath the retina, which may become detached by its growth. Sometimes the parasite perforates the retina and becomes free in the vitreous, where it may be seen with the ophthalmoscope as a clear cyst, from which the head of the worm is sometimes protruded. A less frequent seat is the anterior chamber, Avhere it may be free or attached to the iris. It is capable of protruding and withdrawing its head. The cysticercus also occurs in the orbit outside the eyeball.

The Echinococcus occasionally has its seat in the orbit.