(CNN) - Imagine looking into your irritated eye for a pesky eyelash, only to pull out a translucent, wiggling worm nearly a half inch long.
"I looked at it, and it was moving," recalled 28-year-old Abby Beckley of Grants Pass, Oregon. "And then it died within about five seconds."
Now, imagine doing that not once but 14 times.
That's what Beckley endured over a three-week period in August 2016. Her story, published Monday as a case report by the US Centers for Disease Control and Prevention, is a historic one:
"This is only the 11th time a person has been infected by eye worms in North America, " explained lead author Richard Bradbury, who is the team lead for the CDC's Parasite Diagnostics and Biology Laboratory. "But what was really exciting it that it is a new species that has never infected people before. It's a cattle worm that somehow jumped into a human."
A summer adventure
Growing up on a ranch in Brookings, Oregon, surrounded by cattle and horses, Beckley loved the outdoors. She also had a burning desire to travel. So, in July 2016, she jumped at a chance to combine the two by working on a commercial salmon fishing boat in Craig, Alaska. It was only a couple of weeks into the job that the symptoms started.
"My left eye just got really irritated and red, and my eyelid was droopy," Beckley remembered. "I was getting migraines too, and I was like, 'What is going on?' "
She'd been suffering for five days when the ship finally returned to port. Beckley found a good mirror and looked closely into her eye, never expecting what she would find.
"I pulled down the bottom of my eye and noticed that my skin looked weird there," Beckley said. "So I put my fingers in with a sort of a plucking motion, and a worm came out!
"I was just in shock," she said. "I ran into my crewmate Allison's room, and I said, 'I need you to see this! I just pulled a worm out of my eye!' "
Believing it to be a salmon worm, the women feverishly searched for similar cases on the internet but could find nothing. Visits to a local doctor and ophthalmologist also proved fruitless.
"They said they had never seen anything like this," Beckley said, adding that during that time, she pulled another four worms from her eye. "And then I could see them moving across my eye at that point, too. There were so many."
Worried family and friends encouraged her to return home and set up an appointment at Oregon Health and Science University in Portland. She went directly there from the airport.
"There were several doctors examining my eye, and at first, they were a bit skeptical, because who comes in and claims they have a worm in their eye?" Beckley remembered. "I am thinking to myself, 'Worms, please show up,' because sometimes they would go behind my eye and under the eyelid, and you couldn't see or feel them anymore."
Luckily, she says, after a half-hour, the worms made an appearance.
"I felt one squiggle across my eye, and I told the doctors, 'You need to look right now!' " Beckley said. "I'll never forget the expression on their faces as they saw it move across my eye."
'I tried not to go to the darkest place'
While some of the worms Beckley removed were sent off to the CDC for identification, she frequently visited the university for vision tests and eye washes designed to flush out additional worms. Although her vision remained fine, the flushes were unsuccessful.
"I just kept pulling the worms out of my eye at home, but when I went to the office, they would flush, and nothing would come out," Beckley said. "They were trying to figure out what to do because there was no road map, no protocol for this."
The worst part, she says, was wondering what the worms might do to her body, "so close to my brain and eyes."
"I tried not go to the darkest place, like, are these worms going to paralyze my face or infect my brain or impact my vision?" she said. When a doctor explained that the worms would remain on the surface of her eye, she calmed down.
"I was definitely in distress, for sure, but I also started making jokes, because I had to, to deal with it," Beckley said. "It's so gross to think about, but it was happening to me."
'Fascinating ecological niche'
Parasitic eye worms are common among dogs, cats, pigs, sheep, goats, cattle and wild carnivores like foxes and wolves. The larvae are transmitted by female "face flies" that feed on the animal's eye secretions.
"Tears are full of proteins of various kinds, so the flies get a lot of nourishment from those tears," explained Dr. William Schaffner, a professor of medicine at Vanderbilt University's Division of Infectious Diseases, who was not involved in Beckley's case. "For a scientist, it's a fascinating ecological niche."
The worm larvae grow into adulthood and reproduce between the eye and the eyelid. Their offspring leave the host's body via more secretions from the inflamed eye, which the flies ingest, completing the life cycle.
"The early-stage larvae need to go through the fly's digestive system to be able to develop to a more advanced stage to infect another host," Bradbury explained. "It's a complicated life cycle."
Veterinarians treat the infection in pets and livestock with the anti-parasitic drug ivermectin. But in untreated animals, Bradbury says, the worms can live and reproduce up to 30 months, leading to vision loss or even blindness.
People infected by the parasite typically don't suffer that fate, because, like Beckley, they can remove the worms from their eyes.
Unraveling a medical mystery
When the worms from Beckley's eye arrived at the CDC's diagnostic lab, scientists were expecting to find a species of the Thelazia parasite called californiensis. That's what infected the eyes of the 10 cases found in the US: nine from California and one from Utah.
"It's an eye worm that often infects dogs and very occasionally affects humans," the CDC's Bradbury explained. "Another type of eye worm called callipaeda, found in Asia and Europe, has also infected people, but it's also rare, with only about 163 reported cases in the world."
Most cases of human infection around the world occur in poor, rural communities among the very young and elderly, who may be less able to keep flies from their face. But not always. In 2015, a 21-year-old South Korean soldier developed eye worms from the Asian strain, callipaeda, after multiple brief contacts with a dog in his father's factory.
"He recalled nothing abnormal about the dog," said Dr. Kyungmin Huh, a South Korean doctor who wrote about the case in the New England Journal of Medicine. "But I should note that previous reports show that patients cannot remember how it was transmitted in the majority of cases."
Beckley has no memory of any fly landing close to or in her eye.
"It makes me curious if there was someone else who had this happen but wasn't seen by a doctor," she mused. "The only reason that I knew the cause is that I physically pulled one out of my eye."
Schaffner agreed: "Dollars to doughnuts, there were people in the past that had these infections but were never specifically diagnosed. Here, we have someone who developed this unusual infection, and the physicians were interested enough to send the materials to the CDC, where they have extraordinary diagnostic abilities."
Without that expertise, says Schaffner, investigators may have never noticed the small differences in the anatomy of the worms from Beckley's eye.
"Something was strange about it," Bradbury said, "and we had to go digging to find out what it was. I finally found the microscopic pictures I needed to find the exact species in a paper written in German in 1928."
Bradbury says the species, Thelazia gulosa, is unique to cattle and has never before been seen in a human eye. That means Beckley was infected by cattle near her home, before she left for Alaska.
"It's possible that there are cases that were misdiagnosed as another species of the worm, californiensis, because people just assume that it will be," Bradbury said. "But through our work, we were able to understand that a brand-new species can now infect people who are around cattle."
The end of a nightmare
Beckley was not treated with anti-parasitic medicine because doctors were worried that a dead worm might remain in her eye, possibly causing scarring. Instead, she was told to continue to monitor her eyes and remove any worms she found. How did she handle the uncertainty?
"You can go into 'Poor me, Oh, my God, I'm going to let this destroy me,' or you can just think, 'OK, these are worms, and now I know the life cycle, and I know that they will die, and they are just sharing space,' " she said. "Doesn't mean I wasn't grossed out! It doesn't mean I wasn't angry! But I would try to self-soothe and put it in perspective."
Twenty days after pulling the first worm from her eye, Beckley discovered the final wiggling worm. Once that was out, her ordeal was over. She knows because she's not found another since. Her vision remains good, with no other complications.
But why go public with her story?
"Part of the reason I'm speaking out is that I had wished I could find one article or source that would reassure me this happened to someone else and they are fine," Beckley said. "if this does happen again, I'm hoping my story will be out there for the next person to find."