Ever wonder how your pretty little eyes work? Light goes through the pupil, which is the black hole in the center of your eye. The light becomes an image on the retina, which converts the image into nerve impulses. Your brain reads these impulses and "tells" you what you are seeing. The image that the retina receives is upside down, but your brain reverses it to right–side up. that's it, in a nutshell—or, in an eyeball, if you'd prefer.