An elephant which became the first in England to undergo pioneering surgery to remove a damaged eye is now believed to be almost completely blind after concerns over the health of the remaining eye.
In 2011 Duchess, Paignton Zoo's 42-year-old African elephant, was the first in the country to have an eye removed.
She had the ground-breaking operation because of glaucoma in her right eye. Cataracts left her with limited sight in her left. Now, a routine eye check has shown that what vision remains is deteriorating.
Neil Bemment, curator of mammals and director of operations at the Devon zoo, said: "Consultant ophthalmologist Jim Carter has confirmed that the cataract has worsened since her last check-up four months ago.
"She is, to all intents and purposes, now blind although she can probably still tell the difference between light and dark. In his opinion, she is not in pain which is at least some good news."
Zoo staff have been caring for Duchess's eyesight for some time now, and she has been trained to accept eye-drops and other medication.
She has been on her own since her long-time companion, Gay, a female Asian elephant, was euthanised in March 2010 due to ill health.
Mr Bemment said: "In spite of this, she seems to still be in good spirits and as keen on her food as always. She receives a lot of attention from her keepers.
"Duchess's welfare and quality of life are our primary concern. The chances of an operation to reinstate full sight being successful are not high, the best result might be long sight with limited close vision.
"Elephants have an acute sense of smell and terrific hearing, so she is well aware of things happening around her even if she cannot actually see them. We are, however, considering all of the long-term implications of blindness and will be monitoring her behaviour closely over the coming months."