Despite receiving a pair of perfectly functioning new eyes, his vision was still severely impaired because his brain reprogrammed the visual areas of the brain, utilizing those areas for other sensory purposes.

Ten years after his cornea transplant, Mike still relies on a guide dog to navigate around and is unable to identify facial expressions, demonstrating the complexity of the brain's visual processes. The result was medically successful, but for the patient, overwhelming and confusing, as his brain did not have any semblance of facial recognition or depth perception. Cornea Transplant (02:57)ĭoctors performed a cornea transplant using cutting edge stem cell research on a man who had been blinded at age three. Through millions of years of evolution, the brain combs through information, distinguishes patterns, and assembles a reality. In order to perceive light, sound, and much more, electrochemical signals are fired off in the brain constantly. The brain is located inside the skull, inside the head, which is a sealed chamber isolated from all light and sound. A cast shadow on a checkerboard pattern skews color perceptions, but the brain recognizes the shadow. Passersby examine an optical illusion, finding that the brain attempts to understand color in surprising ways. The brain interprets information and transforms it into a multi-sensory reality. The human brain, a three pound, Jell-O-like mass, is the most complex thing scientists have discovered in the entire universe.

Pbs the brain david eagleman