By firing the flash several times just before exposing a photo, cameras with a redeye reduction feature cause a subject's pupils to contract, reducing the reflection that causes redeye.
minimizes the reflection from the camera's built-in flash
A process which helps elimate the tendency of people's eyes having a red color to it. This process fires the flash twice, one to constricts the subject's pupils (reducing the redeye) and the second to light the scene.
A special flash mode whereby a pre-flash or a series of low-powered flashes are emitted before the main flash goes off to expose the picture. This causes the pupil in the human eye to close and helps eliminate red-eye.
A system that causes the pupils of a subject to shrink by shining a light prior to the taking of the flash picture. This prevents the red-eye effect.
Using a flash in low light conditions (where they are most often needed) can cause subjects to have red eyes. This is caused by the reflection of the flash on the retina of the eye. Many cameras now come with a red eye reduction feature that fires a “mini” flash (or several bursts) of light to fool the iris into closing a bit before the real flash fires. This reduces but does not eliminate red eye.
A mode on many cameras that fires a pre-exposure light or flash in order dilate subjects' pupils and prevent the common problem of red-eye with flash photography. Especially useful when photographing people in low light.