In photos taken at night with a flash, people often appear as zombies with their spooky red eyes. Do you know where the red eyes come from in color photographs? Well, it’s attributable to the light of the flash which occurs too fast for the pupil to close and thus, allowing the light to reflect off of the retinas in our eyes. The bright flash may be too much for the eye to make any possible adjustments to negate red-eye effect.