“The retina is, in fact, the brain: in the development of the embryo, a piece of the brain comes out in front, and long fibers grow back, connecting the eyes to the brain. The retina is organized in just the way the brain is organized and, as someone has beautifully put it, ‘The brain has developed a way to look out upon the world.’ The eye is a piece of brain that is touching light, so to speak, on the outside.” – Richard P. Feynman, The Feynman Lectures on Physics, Vol. I