Definition: Redeye is an effect often seen in digital photographs and prints, where the subjects appear to have red-colored pupils in the eyes when a flash is used when shooting the image. Redeye is caused by a reflection from the light from the flash against blood vessels in the retina of the eye. Beginner-level and low-priced digital cameras are more susceptible to causing redeye than advanced models, because the lens and flash units usually are close together in a low-priced digital camera.
To remove redeye, photographers can try to remove the effect using photo-editing software. Some digital cameras also offer a redeye reduction feature, where the flash changes the way it fires to force less light to reflect off the retina.
