RALEIGH, N.C. (AP) — 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 12,000-pound, 38-year-old African bull elephant has been at the zoo since 1978.

Zookeepers first noticed his eyes were cloudy in 2010. He gradually lost 1,000 pounds, became lethargic and seemed depressed.

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

C'sar's eyes are a bit larger than the eyes of a horse, said Richard McMullen, assistant professor of veterinary ophthalmology at N.C. State. 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.

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, 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 thick steel bars to receive the medicine. With contacts, he would need four-to-five doses daily.

Zookeepers 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.

McMullen said the decision is still "a long way" off and will ultimately be decided by the zoo.

"There are a lot of questions that still need to be answered," he said.

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