Aftervision is a noun that refers to a visual perception or imagery experienced after looking at a bright light source or staring at an image for an extended period of time. It is a form of optical illusion or phenomenon that occurs due to the persistence of vision.
The aftervision typically manifests as a temporary, lingering image that is seen when the eyes are closed or when looking at a blank surface. It is characterized by a ghost-like, shadowy impression of the previously viewed object, appearing in various colors, shapes, and intensities. The duration and intensity of an aftervision can vary depending on factors such as the brightness and duration of the initial visual stimulus, individual susceptibility, and overall eye health.
Afterimages occur due to the physiological processes within the eye and the brain's interpretation of sensory input. Specifically, the retina, the light-sensitive layer at the back of the eye, retains an impression or "photographic negative" of the image for a brief period, even after the original stimulus is removed. As a result, the brain continues to perceive this residual image, creating the phenomenon known as aftervision.
Aftervisions can be observed in various contexts, such as after staring at the sun, flash photography, or even prolonged exposure to specific colors or patterns. Researchers and visual artists have also explored aftervisions as a creative tool, incorporating them into art installations or using them for therapeutic purposes.
