Californian cataract surgery specialist Dr Chris Heichel has operated on thousands of human patients, ranging in age from babies to 105-year-olds, but he has never operated on a gorilla — until now.

The ophthalmologist carried out the first successful cataract surgery on a young western lowland gorilla, named Leslie, at the San Diego Zoo Safari Park in the US.

Working with a team of doctors and veterinarians, he removed and replaced the damaged lens during the operation. 

“Fortunately, the similarities between the anatomy of human and gorilla eyes are great enough to allow us to safely navigate the procedure without complication,” said Dr Heichel, from Shiley Eye Institute at the University of California San Diego Health.