Only those with the steeliest of stomachs should proceed. What you are about to see is video of a living 2-cm worm crawling beneath the surface of a lady's twitching eyeball, then getting extracted. It was there for six years.
The below video shows the horrible worm writhing in the lady's eye, then doctors yanking its squirming body out with tweezers. It looks like a booger crossed with a maggot.
The New England Journal of Medicine reports that the patient had "no systemic or visual symptoms," just this creepy feeling that something was crawling around inside her eyeball. Turns out it was a Loa loa worm, "a nematode whose larvae are introduced into humans who have been bitten by infected chrysops flies in areas of western equatorial Africa." She got it during a trip to Nigeria. Loa loa moves at speeds of "up to 1 cm per minute" in subcutaneous tissue, and can survive for seventeen years in humans. [NEJM via jumpingpiglet, front page image via Dudarev Mikhail/Shutterstock]