American military veteran Aaron James (46), who was the first in the world to undergo an eye transplant, has made significant progress after a year, the BBC writes.

So far, his donor eye has maintained normal blood pressure and flow and maintained its size, unlike donor eyes in animals, which often shrink after transplantation, NYU Langone Health scientists report in a new study.

James has not regained sight in that eye, but researchers hope he may. They said they were "truly amazed" by his recovery.

"The results we are seeing after this procedure are quite amazing and may pave the way for new clinical protocols and stimulate further research into complex transplants," said Vaidehi Dedania, a veteran military ophthalmologist.

The study authors said the electroretinograph test, which measures the retina's electrical response to light, showed that the donor's cones, the light-sensitive nerve cells in the eye, survived the transplant.

In 2023, Aaron James performed the world's first eye and partial face transplant at NYU Langone. And while he can't see through the transplanted eye, a new JAMANetwork study details his promising signs of viability.

James lost sight in his right eye and most of his face was damaged in a work accident in 2021. Last May, he underwent a 21-hour operation involving more than 140 medical professionals.

The donated face and eye came from a male donor in his 30s. During the operation, doctors injected stem cells grown from the donor's bone marrow into the optic nerve to stimulate its repair.

Researchers said that James has passed many important moments. He can eat solid food again and his sense of smell has returned.