An Oregon woman has become the first person worldwide known to have had an eye infestation by a tiny worm species previously seen only in cattle.
Abbey Beckley, now 28, was working on a commercial fishing boat in Alaska in the summer of 2016 when she felt something behind her eyelid two weeks into the trip.
When she got to shore five days later, she tried to dig out what she assumed to be an eyelash, but discovered inflamed skin and a wriggling worm.
Confused, she went to an eye doctor, who pulled out four more worms - but had no idea what it was.
Eventually, she was transferred to an eye specialist in Portland, who sent off samples to the US Centers for Disease Control and Prevention, concluding that she had contracted Thelazia gulosa, a parasite never seen in humans that is spread by flies that feed on eyeball lubrication.
'My left eye just got really irritated and red, and my eyelid was droopy,' Beckley, who was 26 at the time, told CNN.
'I was getting migraines too, and I was like, "What is going on?"'
She eventually found a mirror, lifted her eyelid up and was stunned to pull out a worm.
'I pulled down the bottom of my eye and noticed that my skin looked weird there. So I put my fingers in with a sort of a plucking motion, and a worm came out!
'I was just in shock. 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!"
'I looked at it, and it was moving. And then it died within about five seconds.'
In total, 14 translucent Thelazia gulosa worms, all less than half an inch long, were extracted from Beckley's eye over the course of 20 days.
This species of Thelazia worm was previously seen in cattle throughout the northern United States and southern Canada, the researchers reported in a study published in the American Journal of Tropical Medicine and Hygiene.
They said the study indicates that North Americans may be more vulnerable than previously understood to such infections.
If the worms remain in a person's eye for a prolonged time, they can cause corneal scarring and even blindness, according to the researchers.
'Cases of eye worm parasitic infections are rare in the USA, and this case turned out to be a species of the Thelazia that had never been reported in humans,' said study lead author Richard Bradbury, who works with the CDC's Division of Parasitic Diseases and Malaria.
Bradbury said previously it was thought there were only two different species of these eye worms that infected humans worldwide, and that Thelazia gulosa is now the third.
Beckley, from the city of Gold Beach, located on Oregon's coast along the Pacific Ocean about 40 miles north of the California border, said she is now determined to help any other potential sufferers to understand this baffling condition.
'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.'
Previous cases of such eye worm infections have been reported worldwide, predominantly in Europe and Asia and in rural communities with close proximity to animals and with poor living standards, the researchers said.
Eye worms are found in a variety of animals including dogs, cats and certain wild carnivores.