Joseph Ledesma's world is going dark. The 19-year-old photographer from Edmonton is slowly losing his eyesight.

"I don't really know how much time I have with my eyes so it's kind of scary," he said.

Ledesma has retinitis pigmentosa, a degenerative condition that affects how his eyes respond to light. The disease, which has no cure, causes a gradual loss of vision and ends in blindness.

"Your vision starts collapsing and you get tunnel vision," he said.

Ledesma doesn't know when he'll go completely blind, but said he wants to use the time he has left to work on his photography.

"I like sharing what I can see," he said. "I'm just doing it so people can have memories of what I saw."

Photos of Joseph Ledesma are a bit hard to come by - he is usually the one behind the camera. (Supplied)

Before his diagnosis in September, the full-time student said photography wasn't a priority. He was too busy studying civil engineering at NAIT.

When Ledesma realized his eyesight was fading, he picked up his camera. He said he noticed the disease creeping into his photographs as tunnel vision set in.

"It's my perspective," he said. "It's a little different."

Ledesma documents his work on an Instagram page called The Blind Side.

"I wasn't expecting anything, I just wanted to show my perspective on things and it's just a normal Instagram page and then people started re-posting them and I was just so surprised," he said.

He plans to continue sharing his work online for as long as he can.

"I didn't really plan on doing anything else, I'm not too sure. If it takes me somewhere, then I'll take it," he said.

"It's pretty cool, but then thinking about it, I don't know how long I'll have my vision, right? You've got to cherish those moments."