Romina was sedated during the operation

During the procedure, Romina was sedated and laid out on two operating tables in the veterinary department at the University of Bristol.

Sharon Redrobe, Bristol Zoo Gardens' head of veterinary services, said: "As soon as Romina came round from the operation we could tell that she could see.

"She immediately reached towards food without resorting to feeling her way.

"We're delighted that the operation has been so successful and that she is having the chance to explore her surroundings and companions properly for the first time."

Artificial lens

Ms Watts was assisted by two animal specialists, David Gould, an expert on cataracts in cats and dogs, and Dan Holden, a veterinary anaesthetist.

The operation involved the same procedure that was used to remove a cataract from the late Queen Mother's left eye at London's King Edward VII hospital in July 1995.

An incision was made through the cornea and ultrasound used to break up the cataract.

The debris was removed, and a silicone artificial lens inserted.

Whether Romina's operation is ultimately successful will not be known for another four to seven days.