The “red-eye effect” in photos, is caused by light reflecting off of the retina, especially when a flash is used in dim lighting. People who generally have large pupils, in dim light, tend to experience “the red eye effect” with photos. The red color is due to the rich blood supply of one of the layers of the retina called the choroid.
How to Reduce the Red-eye Effect in Photos?
1. Red Eye Reduction setting on a camera: This gives a little pre-flash before the actual photo is taken, to give time for the pupil to constrict.
2. Brighter lighting in the room: This will also help to reduce the pupil size.
3. Looking slightly off center from the camera.
4. Taking a picture without the flash.
5. Edit the photo afterwards.