Having suffered a tragic childhood, Underwood lost his sight to cancer and had his eyes removed two weeks before his third birthday. But luckily he discovered an almost unique way to overcome this.

He now uses echolocation (returning sound waves) to sense his surroundings. By clicking his tongue he can detect everything around him, much like a dolphin. His skills are so perfected that he can use this sense to practice karate, rollerblading and play basketball.