(CNN) -- Jeremy Poincenot can no longer read, drive a car or even recognize faces.
But the 20-year-old, who lost his central vision two years ago, can successfully hit a small white ball into a slightly larger hole from considerable distance.
Chipping from off the green at a tournament in August, the American won a nerve-wracking playoff to officially become the world's best blind golfer.
Poincenot, a college student from San Diego, has an extremely rare disease called Leber's hereditary optic neuropathy (LHON). And not long ago, he feared he'd never play golf again.
He woke up the day before Thanksgiving in 2008 to notice his formerly perfect vision was a little blurry. A routine trip to the optometrist to pick up a pair of glasses ended up with him being diagnosed with a suspected brain tumor.
The subsequent holidays were spent having an MRI scan, a spinal tap and then a catheter placed in his jugular as doctors struggled to diagnose the cause of his vanishing sight.
It wasn't until his mother discovered it on the Internet that Jeremy was successfully diagnosed with LHON -- a hereditary disease with no treatment and no cure that only affects one in 50,000 people.
Lissa Poincenot has since set up the website LHON.org to support fellow sufferers and their families, and to help raise funds for the USC Doheny Eye Institute, where Dr. Alfredo Sadun is researching a cure.
Faced with the onset of blindness, Jeremy admits he slipped into depression for a couple of months until one afternoon he was jerked back into action.
"I saw this guy who had just lost his wife and baby daughter when a plane crashed down on his house," he told CNN.
"The guy was in a press conference crying, saying 'If anybody knows how to handle something this tragic, please tell me.' I just thought, 'Hey if this guy can make it through this then I can survive having no central vision.' That became my motto: 'Things could be worse'".
So six months after losing his sight, Poincenot decided to pick up his clubs again.
A keen golfer with a handicap of just four, he had played every Sunday since the age of 12 with his Dad Lionel, a club engineer at golf firm Callaway.
CNN
