Mystic — Mystic Aquarium has announced that it performed successful surgery to save the sight in the right eye of a harbor seal named Tori who already was blind in her left eye.

Tori has been at the aquarium since 2012, when she arrived with several health issues. The blindness in her left eye meant she could not be released back to the wild and she took up residence at the aquarium.

Over the past several years, however, she began to develop ocular disease in her right eye.

More recently, Tori’s lead trainer, Lindsey Nelson, the aquarium’s senior trainer of marine mammals including seals, noticed that Tori was keeping both eyes tightly closed for longer periods of time, which is a sign of discomfort.

After medication failed, the aquarium’s chief veterinarian, Jen Flower, began to look into surgical options.

It was decided to create a flap of tissue from the seal’s eyelid and use it to protect the cornea and allow the eye to heal.

Flower said in the aquarium’s announcement that the “new tissue will restore the integrity of Tori’s cornea and bring new blood vessels to the area which will enable the cornea to heal and eliminate the discomfort.” In addition, a medicated implant that will slowly release medication over several months was placed under the seal’s right eyelid.

The aquarium also said that the globe of Tori's nonfunctioning left eye had begun to shrink, causing discomfort, so the decision was made to remove that eye during the surgery.

The three-hour surgery took place Aug. 13 in the aquarium’s new surgical suite in the John T. and Jane A. Weiderhold Foundation Veterinary and Animal Health Center. In addition to members of the aquarium’s animal care staff, the surgery involved veterinary ophthalmologist Ruth Marrion from Bulger Veterinary Hospital in North Andover, Mass., and veterinary anesthesiologist James Bailey from Innovative Veterinary Medicine in Ponte Vedra, Fla.

Six weeks after the surgery, aquarium spokeswoman Dale Wolbrink said Tuesday that the procedure was a success and there has been marked improvement in the seal’s behavior and her interaction with her trainers.

Nelson said in the statement that Tori “is able to see around the flap and is adjusting to her new eyesight. She is no longer keeping her eye closed and is swimming around and locomoting on land very well.”

The seal is in a back pool that visitors do not see as part of the normal movement of animals but is expected to return to the Pacific Northwest exhibit shortly.

Nelson said the experience with Tori has given her a “new outlook on training.”

“We rely a lot on the vision of our animals in order to communicate with them. However, with Tori’s vision impairment, it has made me think outside the box to ensure that I am communicating with her in the best way possible. We have worked very hard on transferring many of Tori’s visual signals for behaviors to verbal signals,” she said.

She added, “Being able to provide Tori with a new lease on life — not once but twice — highlights just how dedicated not only our training staff, but more importantly our vet staff is to the animals in our care.”

j.wojtas@theday.com