A white-tailed deer was found stumbling on the streets of Farragut, Tennessee, with thick hair growing in both eyeballs.
Hair protruded from the discs of flesh that covered the deer’s cornea – the transparent part of the eye that covers the iris and the pupil. The bizarre condition, called corneal dermoids, has been documented in just one other whitetail in the state of Tennessee, according to Quality Whitetails magazine, the National Deer Association newspaper.
A dermoid, by definition, is a type of benign tumor made of tissues that usually appear elsewhere in the body; in that case, skin tissue complete with hair follicles emerging in the deer’s cornea.
The furry-eyed Hart “Maybe I could tell the day from the dark, but I don’t think I would be able to see where it is going,” said Sterling Daniels, a wildlife biologist at the Tennessee Wildlife Resources Agency (TWRA), to Quality Whitetails. “I would compare that to covering your eyes with a towel. You could say day at night, but that’s all.”
The same deer tested positive for epizootic hemorrhagic disease (EHD), which can cause fever, severe tissue swelling and loss of fear in humans, according to the Cornell Wildlife Health Lab. This may explain why the disoriented animal wandered down a suburban street in late August 2020 and seemed to miss out on people nearby, Quality Whitetails reported.
However, the disease does not explain why the deer ‘s eyes sprouted tufts of hair.
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The patches of hairy skin probably formed early in the animal’s development, while it was still in the womb, Dr. Nicole Nemeth, associate professor in the Department of Pathology at the Southeastern Cooperative Wildlife Disease Study (SCWDS) at the University of Georgia vet school , said Quality Whitetails. Instead of successfully developing into a transparent cornea, the tissue formed skin and hair follicles, obscuring the eyes of the growing deer.
Under the thick hair, the deer’s eyes contained all the expected anatomy.
Despite being born with corneal dermoids, the male lived more than a year and even grew his first pair of horns before getting EHD, which has no treatment, reported Quality Whitetails. Because the deer has survived for so long, Nemeth said the dermoids probably “developed gradually”, allowing the animal to adapt to its decreasing field of view over time.
“How fast [dermoids] developing over time is probably not well known and can vary from case to case, “Nemeth told Quality Whitetails.
Humans can also develop dermoids in the eyes, causing hair to grow in the eyeball, Live Science previously reported. The condition is rare, so an ophthalmologist may see only one or two cases in his entire career. Not all of these dermoids cover the center of the cornea, as in the case of the deer; some dermoids form at the intersection of the cornea and the white part of the eye, called the sclera.
In that case, the condition can cause blurred vision, but it generally does not cause extreme vision problems, Live Science reported. Dermoids can be removed for cosmetic reasons, but removing them does not usually improve patients’ vision.
(You can read more about the hairy-eyed deer case at Quality Whitetails Magazine.)
Originally published on Live Science.