Some pretty sick things can crawl into your body.

Nematode worms can cause a condition called Loiasis, which is transferred through a bite from a African deer fly. The larva of these worms gets into the bloodstream, where it then develops for a few months into adulthood, and can migrate to the eye.

Adult worms can be seen underneath the skin or in the eye, and that's when action is taken to get rid of the monsters. If the worm gets to the eye, if can cause pain, itching, and light sensitivity. Sometimes, there are no symptoms at all. If the worm infection is not treated, it can cause damage to the kidneys, heart, lymph glands and lungs.

Surgery can be done to remove the worm from the eye. A surgeon uses just a little anesthetic, cuts the eye open, and removes the worm. Oh, the patient is still conscious through it.

If just the thought of the worm in your eye doesn't freak you out, watch the procedure to remove the wicked thing. This video is pretty disturbing, so watch out for where you watch it and who you show it to!