In 1959, Bela Julesz, a vision scientist, psychologist and MacArthur Fellow, invented the random dot stereogram while working at Bell Laboratories on recognizing camouflaged objects from aerial pictures taken by spy planes. At the time, many vision scientists still thought that depth perception occurred in the eye itself, whereas now it is known to be a complex neurological process. Julesz used a computer to create a stereo pair of random-dot images which, when viewed under a stereoscope, caused the brain to see 3D shapes. This proved that depth perception is a neurological process.