A negative afterimage occurs when you stare at a bright image for a prolonged period and then look away at a neutral surface. The intense light temporarily fatigues the photoreceptors in your eyes, causing them to send signals that create a reversed color version of the original image. For example, if you look at a red object, the afterimage may appear green. This phenomenon is a result of the way our eyes and brain process visual information. The cones in our eyes, responsible for color vision, become less sensitive to the colors they have been exposed to, leading to this temporary visual effect.