The ghosts we see: Afterimages provide clues to how our brains perceive a stable environment

Our eyes alone do not provide us with a continuous and stable view of the world. They jump several times each second in rapid movements called saccades. Because the eye projects the world onto the retina, we should see the world shift abruptly each time the eyes move; the visual scene should feel unstable. However, the brain uses sophisticated mechanisms that ensure it does not.