Daniel Kish: Man who is blind but can see like a bat
Daniel Kish, who is completely blind, demonstrates how he uses a form of echolocation to describe what's inside a park he's never been to before.
He lost his sight as a baby when he was diagnosed with retinal cancer and now has prosthetic eyes.
He makes clicking noises with his tongue and creates a mental image of his surroundings from the reflected sound.
He now trains other people who are blind to 'see' the same way he does.
The BBC followed him around as he tried to teach his skills to a ten-year-old boy from Scotland.
Hear the full story here: Batman and Ethan