LOOK: This Deer In Tennessee Has Hairy Eyeballs

What caused a deer in Tennessee to have hairy eyeballs? The creature's condition is said to be quite rare.

It was late August 2020 when a report came in from Knoxville, Tennessee, about a deer with "something" on its eyes. According to the National Deer Association (NDA), Sterling Daniels of the Tennessee Wildlife Resources Agency (TWRA) said that the animal seemed "bleeding" and has little awareness of the people around it.

It was found later that the deer actually had hair growing out of both of its eyes. In the image shared by the NDA via Twitter, one can see the thick, hair-like growths on its cornea.

According to the report from the Southeast Cooperative Wildlife Disease Study Unit (SCWDS) of the University of Georgia, the young deer actually had corneal dermoids.

What Are Corneal Dermoids?

"Dermoids are a type of choristoma, which is defined as normal tissue in an abnormal location," Dr. Nicole Nemeth and Michelle Willis said in the SCWDS report. "Accordingly, dermoids are characterized by skin-like tissue occurring on the body in a location other than on the skin."

As the NDA explained, a corneal dermoid is essentially a "glitch" in which the corneas develop benign skin-like tissue instead of corneal tissue. This also means the development of skin characteristics such as the presence of hair and sweat glands. It can affect one eye or both, the SCWDS report noted.

In the case of the young deer, it clearly developed substantial hair on both of its corneas.

Since it is believed to be a congenital condition, the young deer likely had the condition since birth and possibly experienced decreasing vision as the condition gradually progressed, Dr. Nemeth said according to the NDA.

By the time it was found, it's possible that the deer couldn't see anymore, Daniels surmised.

"It maybe could tell day from dark, but I wouldn't think it would be able to see where it was going," Daniels quoted as saying by the agency. "I'd compare it to covering your eyes with a washcloth. You could tell day from night, but that's about it."

"Frankly, it is impressive the young buck was able to survive as long as he did," the SCWDS report noted.

Rare, But Not Dangerous

Apart from the vision obstruction, corneal dermoids don't pose a health threat, SCWDS explained. In fact, even humans can also have it.

According to Live Science, humans can also develop dermoids in their corneas, but it is considered quite rare. The growth can also be removed, although it won't really improve the person's eyesight, the outlet explained.

And in animals, corneal dermoids have been reported in several species but not so much in deer. According to the SCWDS, the deer reported in August was actually just the second reported corneal dermoid in a white-tail deer. The first was a young doe in Louisiana that a hunter killed in 2007.

As for why the buck was behaving rather strangely when it was found, it's apparently not just because of the vision problems brought by the corneal dermoids. The deer also tested positive for epizootic hemorrhagic disease (EHD), a condition that Cornell Wildlife Health Lab (CWHL) explained to affect white-tailed deer primarily.

Deer afflicted by the condition, CWHL said, may lose their fear of humans, possibly explaining the young deer's odd behavior at the time it was found.

"It is not clear whether this buck’s abnormal behavior was attributed primarily to HD, corneal dermoids, or a combination," the SCWD report noted.

So far, there is no treatment for EHD. Deer infected with it tend to "die quickly" within hours.