SAN ANTONIO -- Thursday afternoon, 6-year-old Alejandro Ortiz will undergo a half-hour operation that is expected to restore his slowly deteriorating sight.

Two years ago, a standard pre-kindergarten vision test revealed Ortiz had a one-in-a-million eye disease known as congenital endothelial dystrophy, or CHED, said ophthalmologist Kenneth Maverick.

"The back layer of (Ortiz's) cornea has gone bad and his world is like looking through a foggy shower door," he said.

To fix the problem, Maverick will remove the damaged cornea and replace it with a healthy donor cornea.

"It just so happens to be the right type of transplant for this little boy," Maverick said.

While common in adults, Maverick said of the procedure, the transplant operation is rare for children, meaning Ortiz is one of the first to undergo the procedure -- and it almost didn't happen.

The Ortiz's insurance company refused to pay for the procedure, his parents said. That prompted the doctors and staff involved to volunteer their services for the procedure. Rene Ortiz, Alejandro's father, said he's very appreciative for the medical services as well as for the family of the young man who chose to donate his organs.

"Somebody's going to get a letter that says his cornea went to a 6-year-old boy," Ortiz said. "How lucky for that family. How lucky for us."

Maverick said the operation typically has a 90 percent success rate, but if Ortiz's body rejects the cornea, they can easily try again.