Red eye Bashny.Net

When we see in photographs or films about the nature of the animals' eyes in the headlights, we see that these eyes shine brightly, reflecting the light. A human eye in photos, it happens otblёskivayut red. What caused this glow?





Glitter red human eyes can be compared with the brilliance of the moon. This is the light that came from another, larger source and then reflected eyes. The flash chamber passes through the pupil and reaches the back of the eye - the retina. The retina, in turn, reflects the light back to the camera, but it does it very peculiar. Like other viscera of the body, the retina is a very unsightly chaos of the blood vessels. They are the reason that the light reflected from the retina, it turns red. We literally paint the light of his own blood.

But what about the animals' eyes? After all, dogs, cats and deer also have blood, but their eyes on the photos do not look like the eyes of a vampire. Their eyes shine in the dark because of the special layer, which is located behind the retina of the eye. This layer is called the «tapetum lucidum» (lat. Tapetum - blanket). And it reflects the light directed into the eye of the animal, because it is - it is something for which it is intended. Cats, dogs, deer and other nocturnal animals have good night vision because the light, got into their eyes immediately reaches this particular layer behind the retina, almost without affecting the photoreceptors. The light is then reflected from a particular layer, again passes through the eye of the animal. In this way, the animals receive more photons from the object that they are considering.

The reflectivity of the tapetum lucidum layer is much higher than the reflectivity of the retina. Redness in the eyes of the animals is not observed because the color red is replaced with a substance that makes up the reflective layer. Although the pigments of the retina and pupil also affect the color of the lights, but this effect is very small, and most of the light reflected from the eye of the animal, goes back almost unchanged. It is because of the absence of a special layer of the eye in humans appear red. And they look so only in photographs, not in the rays of the lantern. At the low reflectivity of the retina, and it can shine only during very strong and short flashes. Camera flash gives a huge amount of light, and this light is directed at the face. Some cameras can remove "red eye", making two flashes for a very brief period of time. During the first outbreak of our pupil reflex is compressed, and does not let in too much light eyes, which can then be reflected by the retina, and because of which our eyes on the photo will look like vampire eyes.

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