Erik Weihenmayer lost his vision at age 13, but he never lost his thirst for adventure. In the decades since, he has rock-climbed in California and ice-climbed in Antarctica. In 2008, he decided he wanted to kayak through the Grand Canyon. It was, as you can, imagine quite a ride.
Read more about Erik on his website, listen to his podcast, or follow him on Twitter. You can watch his documentary, The Weight of Water, on Amazon.