The evolution of human vision is linked directly to our perception of the world around us, and therefore also associated with the development of astronomical science. In this talk we will discuss the main characteristics that define the camera called the eye and the mechanisms associated with visual perception in the brain, and present some implications of the issues discussed, including the detection of historical supernovae and the determination of their light curve, the discovery of the Orion Nebula and the illusion, popularized by Lowell, known as the "Mars channels".