19-year-old contact lens wearer, Jessica Greaney, thought she only had a minor eye infection: her eye was sore and her eyelid kept drooping. "But, by the end of the week, my eye was bulging, and it looked like a huge red golf ball," Greaney said. "It was swollen, and extremely painful, and they admitted me into hospital."
Little did she know that there was a parasite, Acanthamoeba, living inside her eyeball. Left untreated, this parasite can cause blindness. To diagnose the problem, doctors had to scrape away a small sample of her eye tissue with a scalpel.