We often see the vampire or zombie look in some of our images. This phenomenon occurs in night or very low light when the images are captured in the presence of flash. Now the question is how does this phenomenon of red eye occur in dark environment? In layman’s terms it simply occurs due to our eye’s interaction with the camera’s lighting mechanism. If we explain, it works as follows. The red color from the light of the flash is reflected from the retina of our eyes. We will often see when we are capturing our pets in low light, almost every image has a red eye problem. It is mainly because in animals the retina has a unique layer called tapetum lucidum which acts as a mirror from the back. If we notice their eyes in presence of bright flashlights we will see their eyes reflecting back that the bright white light. Even though we, humans don’t have this specific layer in our retinas, but when we try and capture an image in the dark using the flash, the flash of the camera is bright enough to cause a reflection off the retina. It is nothing but the red color from the blood vessels in our eyes. Even people with low amount of melanin will experience the incident of red eye because of the fact of melanin being a light absorbing pigment in eye. So people with less melanin will absorb less light and reflect more light causing the red eye effect in the images.
