You know those moments when you learn about something that freaks you out so much, you’ll remember it years later? You’re about to experience another one.

An 18-year-old British college student nearly went blind after her eyeball swelled up to the size of a golf ball. What made it swell so badly? Oh, it was just a parasite that had burrowed into her eye and was eating her cornea from the inside out.

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Jessica Greaney told her student newspaper, The Tab, that she thought she had an eye infection but went to the hospital after her eyeball became out of control. After originally misdiagnosing her with an ulcer, doctors told her the parasite Acanthamoeba Keratitis was burrowing into her eye.

As if that weren’t freaky enough, doctors clamped open her eye and scraped off a layer with a scalpel (it was sent for testing). She then had to have eyedrops to kill the parasite administered every 10 minutes over seven days, leaving her unable to get sleep.

“I wasn’t allowed to sleep properly for nearly a week,” she said. “It was not dissimilar from Chinese water torture. After the fourth day, not only was I going insane and crying every five minutes, nothing was changing.”

Click for more from The New York Post.