CNET también está disponible en español.

Ir a español

Don't show this again

Christmas Gift Guide
Sci-Tech

Meet the parasite that can burrow its way into the human eye

A 19-year-old college student in England contracted a microscopic parasite called Acanthamoeba that started eating her left eye. The other scary part: how she got it.

acanthamoeba.jpg
Meet the Acanthamoeba, the tiny parasite that can crawl into a human eye.Wikimedia

Remember the first season of FX's "The Strain" and how disgusted some people were by the sight of a worm digging its way into a woman's eyeball on posters and billboards (Google the picture if you must, we won't link)?

Well, just imagine the dry heaving they'll be doing when they learn about a very real parasite that can do the same thing (without the turning-people-into-vampires part, of course).

Jess Greaney, a 19-year-old college student at Nottingham University in England, went to the hospital in March with what she thought was just a severe eye infection: a drooping eyelid, pain, swelling and redness in her left eye. Doctors discovered it to be a parasite called Acanthamoeba feasting on her eyeball, according to an article Greaney contributed to the student-focused paper The Tab.

The scary part (as if having your eye eaten from the inside out wasn't scary enough) is how she caught it. Doctors told Greaney that she'd probably contracted the microscopic parasite through contaminated tap water that got into her contact lens.

According to the Centers for Disease Control and Prevention, the microscopic parasite is "found worldwide in the environment in water and soil" and you can pick it up by breathing it in, getting it in cuts or via contact lenses. Most people will come into contact with it at some point -- without getting sick. The bad news is if you do, it causes a condition called Acanthamoeba keratitis, which "can result in permanent visual impairment or blindness."

Can this sound any scarier? Yes. Yes, it can. Thanks to early detection, they were able to save Greaney's cornea, but a surgeon had to scrape layers of infected tissue from her eye with a scalpel while her eyelid was kept open with a clamp, Greaney said. For the first four days after surgery, she was woken up by a nurse every 10 minutes with eyedrops, and was required to keep using large amounts of eyedrops after that.

The CDC says that prescription medications exist that can treat the infection but noted that it can be "difficult to treat."

The best treatment for any infection is prevention. The Environmental Protection Agency recommends using "commercially made sterile solutions" to clean lenses before putting them on your eyes and to avoid cleaning them with tap water or homemade solutions. People who wear lenses should also avoid swimming with them, even in pools that have been chemically treated or cleaned. Also (and I can't believe we have to warn people not to do this), no one should ever wear someone else's contact lenses.

If you're not completely frightened and haven't sewn your eyelids shut by now, you may be interested to read about the effects of another microscopic organism that can live in the human eye, the Ebola virus.

Sleep tight.

(Via IFLScience)