Aftercolor

Aftercolor refers to the visual perception that persists after a stimulus has been removed. It is a phenomenon related to the way our eyes and brain process color and light. When we look at a bright color for a sustained period and then shift our gaze to a neutral surface, such as white or gray, we often see a faint, ghostly image of the original color's complement. For example, looking at a red object for a while and then at a white wall may result in seeing a green afterimage. This is due to the fatigue of photoreceptor cells in the retina. Specifically, the cones responsible for detecting the fatigued color become less responsive. When the eye is then exposed to a neutral stimulus, the remaining, less fatigued cones send stronger signals, creating the perception of the complementary color. Afterimages can be either positive, where the color is similar to the original stimulus, or negative, which is the more common type described above and is based on complementary colors. The duration and intensity of an afterimage depend on factors such as the brightness and saturation of the original stimulus and the length of time it was viewed.