Why are your eyes red in pictures?

Answer 1

You are actually seeing images of the retina, the layer of cells at the back of the eye. There are many blood vessels in that part of the eye, as well as a very high concentration of light receptor cells.

You will note that in virtually every photo in which you see 'red eye', the photographer used a flash. The flash was probably on the camera, making it possible for light from the flash to make a reasonably direct trip from flash to retina and back to the camera. The need for the flash suggests that the ambient light level is low enough for the subjects' irises to be open. The flash and exposure happen so quickly that the iris doesn't have time to adjust by closing a little. The result is the slightly creepy effect that we call red eye.

This is why most cameras today have a pre-flash option for photos of people and/or animals. A few short bursts of light cause a person's irises to close a little, and red eye is almost always avoided. If this option is not available with your camera, then placing the flash at an angle, away from the camera, may also help reduce red eye. The problem can also be fixed easily with most photo editing software packages.

Answer 2

when a camera flash is pointed directly into your eyes, the light travels through your pupils. the camera actually takes a picture of the insides of your eyes. there are so many blood vessels in your eyes the camera sees red.

Answer 3

Humans have a curved plate covering the back of their eyeballs called the retina. This is the part of the eye that actually detects the presence of light. When the flash on a camera fires, the bright, white light emitted by the bulb travels into the eye, and because the retina cannot absorb all the light, it reflects some of this. But the reflection appears red because the reflected light has to go through the red blood cells of the choroid, and so the eye appears red.

Answer 4

Your camera is recording the reflection from the blood vessels of the retinas at the back of your subject's eyes. The phenomenon is made worse in dark conditions because your subject's irises are open wide, exposing more of the blood-rich retinas.

The phenomenon is not a function of flash as such, but rather of the angle of reflection. There is a physical law which states that the angle of reflection is equal to the angle of incidence.In other words, light bounces off a reflective surface at an angle the same as the angle the light came from. On most compact cameras, the flash is sitting right next to the lens, so the angle of incidence (where the light comes from) is essentially the same as the angle of reflection. The light bounces straight back into the lens. Since the back of the eyeball is richly supplied with blood vessels, the color of the reflection is red and you get those eerie vampire eyes.

What can you do? If you have a flash which can detach from your camera on a cord, you can remove the flash and hold it a foot or more away from the lens. The reflection will go off on the opposite angle and there will be no red eye. But most compact cameras have fixed flashtubes sitting right next to the lens. Manufacturers have devised all sorts of redeye reduction schemes. One of the most common is the rapid repeated low-power firing of the flash before the main flash. This causes the subject's irises to react by closing down, reducing the reflection from the retinas. If you don't have redeye reduction, try raising the light level in the room. If that spoils the mood, try having your subject look into a nearby lamp just before taking the picture. Your subject can also look slightly away from the lens.

If none of that works, or spoils the spontaneity, there are redeye removal pens to retouch your prints. On your computer there may be redeye removal tools. If you have any version of PhotoShop, redeye removal is a cinch.

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Most cameras have that funny pre-flash flicker before the flash; that is so that eyes have a chance to adjust, and avoid the red-eye effect. Serious amateurs and professionals avoid red eye by not having the flash so close to the axis of the lens. This is the primary cause, which unfortunately, many people can't do much about with their simpler cameras.

Answer 5

First, let's determine how eyes turn red. The tissues of the eye need oxygen and nutrients, so they have a blood supply through small vessels (all except the clear cornea over the pupil, which gets oxygen from the air). When our eyes are their usual white, the vessels are not dilated and are almost invisible. When our eyes get red, the vessels are dilated, and we see the blood in them against the white background. This means that whatever makes the blood vessels in the eye dilate will make them red. What makes blood vessels dilate? This is actually a wonderfully complex subject. However, to keep it simple, let's say that whenever a need for an increase in blood supply occurs, the vessels dilate in response to a variety of signals, some through the autonomic nervous system, others from substances released into the blood or surrounding tissues. An increase in blood supply can be needed for more oxygen or for other needs. OK, now, why when we are crying? We cry as the result of increased secretion from the lacrimal glands that keep our eyes moist. The secretion rate of these glands is controlled by the autonomic nervous system and by other signals in the blood. (See where we are going here?) When you cry, the fluid making up the tears has to come from somewhere; it is derived from the blood supply to the glands. Therefore, when you cry, the blood vessels to the glands have to dilate to provide the fluid for the tears. This is accomplished by the autonomic nervous system. If the crying is intense enough, the blood vessels on the surface of the eye also dilate.

Answer 6

The pupil of the eye appears red in some photographs because the light from the camera flash reflects off of the retina at the back of the eye. The light reflects red because of the blood vessels at the back of the eye. This light sometimes comes back out of the pupil and shines through the lenses of the camera.

This can be prevented with a red-eye reduction feature of the camera. This will give a couple warning flashes before the picture is taken, causing the pupil opening to narrow and thus reducing the chances of light reflecting back out of the eye.

Answer 7

we sometimes appear in photographs with red eye. why

Answer 8

Camera flashes make eyes appear red because the light is reflecting off of the retina. The red colour comes from the blood vessels that exist in the eye.

Answer 9

Our eyes do appear red in Photography sometimes because of the camera lightening. This happen especially when we take photo inside house.