Boy learns echolocation

Ben Underwood (1992-2009) lost his eyes to retinal cancer at the age of 3. He developed a type of echolocation allowing him to "see" by using his tongue to produce clicks and listening for the echoes as they bounced off objects. In this way he was able to rollerblade, ride a bike and play sports, among other things. Sadly, he died of brain cancer at age 16.