Visual Reality

Our eyes are literally our windows on the world. Like a camera, they have lenses for focusing, an iris to control the amount of light and a sensitive screen, the retina. The key lies in the retina. It has cells that are so sensitive they can pick up only one or two particles of light, and others that can discriminate thousands of different colors and hues. Since the retina itself is part of the brain, it starts to analyze the images before the brain takes over. Between them, they correct false colors, distortions where blood vessels cross the retina, a whole blank at the "blind spot" where nerves leave the retina, and smooth over blinks so we are not even aware any information is missing.