This undated photo provided by the College of Veterinary Medicine Department of Educational Media and Design shows Richard McMullen, assistant professor of veterinary ophthalmology at North Carolina State University, and second year resident Julie Hempstead, perform cataract surgery on C'sar the African bull elephant at the North Carolina Zoo.

Raleigh, North Carolina - After C'sar the bull elephant lost weight, grew depressed and underwent surgery because of eye trouble, his keepers at a North Carolina zoo began to consider a pioneering move in pachyderm medicine: giving him a set of king-size contact lenses.

Officials at the North Carolina Zoo in Asheboro and the North Carolina State University's College of Veterinary Medicine are weighing whether the risks are worth it. C'sar's caregivers said an elephant has never been fitted with corrective lenses, and they are unsure if they want C'sar to be the world's first test subject.

The 38-year-old African bull elephant weighs 5,443 kilograms and has been at the zoo since 1978.

Zookeepers first noticed his eyes were cloudy in 2010. He gradually lost 453 kilograms, became lethargic and seemed depressed. C'sar's bones were showing through his shoulders and his handlers had to pull him from the exhibit.

“He just stood around and leaned against the walls,” said senior veterinarian Ryan DeVoe. “He was just not interested in anything going on around him.”

After C'sar had cataract surgeries in October and May, he perked up and started regaining weight. The other day, DeVoe said, the invigorated elephant swung his tusks at him while eating a sweet potato - an encouraging display of dominance.

However, when the natural lenses from both of his eyes were removed, the animal was left farsighted.

“He might not see perfectly, but he thinks he sees well enough to be moving around,” said Richard McMullen, assistant professor of veterinary ophthalmology at N.C. State. “They said he's been running around, and they haven't seen him do that in quite some time.”

C'sar's eyes are about as large as racquetballs, McMullen said, which means they are a bit larger than the eyes of a horse. The lenses would need to be soft and almost three times larger than contacts fitted for a human: 38 millimeters in diameter and about half a millimeter thick. It will be August at the earliest before C'sar's eyes are sufficiently healed to wear contacts. McMullen said he mainly applies contacts to horses, and corrective lenses for animals are almost exclusively used for dogs.

German-based Acrivet would create the contacts if called upon by C'sar's caregivers. A spokeswoman said the technology for animal contacts has only been around for a little under a decade and the company has never made elephant contact lenses before. The custom creations for C'sar would be the largest the manufacturer has ever made. McMullen said he hasn't received a price quote on the lenses, but said non-correct lenses for horses cost about $160 each.

McMullen, who performed C'sar's two surgeries, believes corrective lenses would further improve the elephant's wellbeing.

“In dogs, we have seen their quality of life increase,” McMullen said.

The elephant wouldn't have to go under anesthesia to get the contacts inserted, but he might have to be sedated.

C'sar already responds well to his post-surgery eye drops. The bull elephant's handlers have trained him to lean his eye in between the six-inch (15-centimeter) thick steel bars to receive the medicine. With contacts, he would need four-to-five doses daily.

Zookeepers are weighing the unknowns of being the first to pioneer elephant contacts. They aren't certain how often the contacts would need to be changed. Their best guess is every three months. Zoo officials also don't know what health complications might arise over time.

While this would be the first corrective lens for an elephant, it wouldn't be the first contact. McMullen said a contact has been used once before on an elephant in Amsterdam in February, but just as a bandage to keep foreign objects out of the eye after surgery.

Still, McMullen said the decision is still “a long way” off and will ultimately be decided by the zoo.

“There is really not any information out there on leaving contacts in for longer amounts of time and effects on the cornea,” McMullen said. “There are a lot of questions that still need to be answered.” - Sapa-AP