A Canadian who suffers from a form of retinal degeneration has had some of his sight restored after undergoing an experimental procedure in the United States.

Dale Turner of Peterborough, Ont., suffers from Leber congenital amaurosis (LCA), a degenerative illness that leads to blindness as the retina becomes so damaged it can no longer process light.

In January, Turner became one of only a handful of people to undergo the procedure when surgeons at the University of Florida injected his right eye with millions of copies of a gene called RPE65. This gene is mutated in people with LCA.

Turner, who only had about 10 per cent of vision, said his sight improved almost immediately.

"I'll never forget it. It was a Sunday morning," Turner said.

"I went outside, peered into the sky. I had never seen the sky that blue, that intensity. It was an emotional moment."

Turner's grandfather, John, was awestruck that such a breakthrough was available to his grandson, who previously had no vision in either of his eyes.

"When you consider the procedure they did on Dale, it's truly amazing," he said.

Turner, a 21-year-old Trent University student, was diagnosed with LCA at the age of 5. He was able to continue playing sports, and he reads by using a machine that turns print from black letters on a white background to white letters on a black background.

He expects to have a larger dose of the healthy genes injected into his eyes in the hope of inducing an even greater improvement in his vision.

"It means being able to recognize a classmate across the room," Turner said about the procedure's impact on his life.

"It means not tripping over things as much. It means less embarrassing situations. All these things add up to such a better quality of life for me."

Turner's procedure was conducted by a third research team investigating the procedure. Two other research teams, one American and one British, studying this gene therapy published their research this week in The New England Journal of Medicine.

The studies showed that four out of six people injected with the healthy genes had steady vision improvement for several months after the procedure. The patients could read some letters on an eye chart, and one patient could navigate an obstacle course that he previously could not.

Symptoms of LCA begin in early childhood, and patients lose their sight completely by the time they are in their twenties or thirties. There is no treatment or cure.

Speaking on CTV's Canada AM last week, Dr. Robert Koenekoop of Montreal Children's Hospital said that the findings are a major breakthrough.

"I believe that this is one of the most significant advances in human history in the field of medicine, to be able to treat a complicated retinal disease that we thought only ten years ago was untreatable," Koenekoop said.

Based on a report by CTV's medical correspondent Avis Favaro and producer Elizabeth St. Philip.