A 36-year-old woman in Germany was surprised to find a "moving wormlike" creature trapped behind her eyelid.

In a case study published in the New England Journal of Medicine, researchers said the woman found something moving in her eye after returning from a work holiday. The unidentified woman was an anthropologist and had traveled to the Central African Republic as part of her job.

She went to a hospital to find out what was wriggling inside her eye. Doctors performed several tests and she was diagnosed with a parasitic infection known as Loiasis, which was caused by Loa loa worms.

Loa loa – literally meaning "worm worm" – is an "eye worm" native to Central Africa and is normally transferred through the deer fly. It is a type of parasite and can produce inflammatory swelling. The infection caused by the worms is referred to as a Calabar swelling, according to the Centers for Disease Control and Prevention (CDC).

Diagnosis of loiasis can be difficult, especially in light infections, CDC says, adding that the specialized blood test is not widely available in the United States.

The German woman was given a 20-day course of medication, which included anti-inflammatories. She recovered after six months. It was not clear when the woman got infected. The exact date of the treatment was also not revealed.

Such cases of parasitic infections occur particularly among those working around livestock, Yahoo News Australia reported.

In 2016, 14 worms were removed from the eyelid of a woman from Oregon, identified as Abby Beckley. She was infected with Thelazia gulosa eye worms. It is believed that she contracted the infection after she spent time horseback riding and fishing.

"I'll never forget the look on the intern's face when he saw one squiggle across my eye," she said about her visit to the ophthalmologist at the time.

Beckley was reportedly the first known person in the world to get infected with the eye worm. "It felt like when an eyelash is poking you," she said back in 2018.

Tapeworm (Taenia) eggs
Pictured: Representative image of tapeworm eggs as seen under a microscope. Ciência e Saúde XXI/Wikimedia Commons/Public Domain