What is red eye reduction in camera and how does it work to improve the quality of photographs?

Red eye reduction is a feature in cameras that helps reduce the appearance of red eyes in photographs taken with a flash. It works by emitting a pre-flash of light before the main flash, causing the subject's pupils to contract and reducing the reflection of light from the retina, which is what causes red eye. This helps improve the quality of photographs by making the subjects' eyes appear more natural and less distorted.