Photo by Simczuk / Kasia via Flickr Creative Commons
A couple of elephants horsing around ... or maybe they just don't see that well
Getting contact lenses is usually a pretty simple process; you visit an eye doctor and get a prescription. But what if you are more than 10 feet tall, have cataracts and weigh around 12,000 pounds? Then you'd be C'sar, an African bull elephant at the North Carolina Zoo that may be getting fitted for contact lenses.
It can be hard to tell when animals go blind. They are so adaptable and know their environments so well that you'll find birds who fly around as if their vision is perfect and when you look closely, their eyes are cloudy to the point of total blindness.
In C'sar's case, employees at the zoo could tell he was clearly not doing well. Dr. Ryan DeZoe, senior veterinarian at the North Carolina Zoo, said that C'sar was slumping against walls and lumbering around.
"With C'sar we were able to see some indication of it in his behavior; he eventually just started having a real hard time getting around. Initially he would bump into things or stub his toe or have a hard time finding his food. Over time, it became more obvious that this was a significant problem for him," he said.
The idea of using contact lenses came up almost as an afterthought. Previous surgeries for C'sar's cataracts were successful, but only to a degree.
"Typically when cataracts are removed from people or dogs or cats… the standard of care is that after that cataract is removed a prosthetic lens implant will be put into place to help correct the animal or the person's vision," DeZoe explained. "The internal structure of his eyes is not strong enough and healthy enough to hold these implants. In C'sar's case, this leaves him considerably far sighted."
The veterinary ophthalmologist thinks his vision is off by 9 diopters. Human vision is corrected at +- .75, this is +9.0.
According to DeZoe, the contact lens will be approximately four inches in diameter. "An elephant's eye isn't quite as big as people may think; they're probably more the size of a racquet ball or tennis ball."
The veterinarians plan to slowly introduce contacts to the elephant once his eyes are completely healed, first by seeing if the lenses will even fit his eye. But one thing they're worried about is whether C'sar will reject the contact lenses.
"If we can get them in will he keep them in? If it's something where he pops them out every five seconds and loses them like crazy, it might not be a practical thing for us to work with," DeZoe said.
DeZoe said that getting C'sar to accept the contacts is entirely up to the animal. "Elephants are pretty smart critters and they're very dexterous with their trunks, so I have a feeling if those contact lenses go in his eyes and he doesn't want them in there, they're not going to stay very long."
Dr. Ryan DeZoe, senior veterinarian at the North Carolina Zoo, joins the show to discuss C'sar's condition.