Definition & Meaning of "red-eye effect"

What is the "red-eye effect"?

The red-eye effect occurs when a camera's flash reflects off the blood vessels in a subject's eyes, causing the pupils to appear red in the photograph. This usually happens when the flash is positioned close to the camera lens, leading to the light reflecting off the retina and showing up as red spots. The effect is most common in low-light conditions where the subject's pupils are dilated. It can be minimized by using red-eye reduction features on cameras, positioning the flash away from the lens, or editing the photos to correct the red coloration.