Friday, April 6, 2012

The Eyes of an Animal - How They Differ from Ours


Have you ever wondered about the eyes of an animal, and how they differ from ours? Not only in shape, size and color...but in vision.

I am not an expert by no means on animals eyes, but decided to do some research and share with my readers.

One question that I was interested in was, why do animals have luminous eyes at night? Why do some animals' eyes shine red at night and some yellow?

I found out:

The eyes of many animals, but not humans, contain a reflective layer called the "tapetum lucidum".  That helps the eye gather more light, which improves night vision.  You just see what's reflected back at you; the rest of the light is absorbed by the creature's eye.

But it's not a precision mirror, and it tends to give you less accurate vision during the day.  Humans go in for precision (which is why we can read) at the expense of hunting or seeing predators at night.

The tapetum lucidum is reflective, but it's not like a mirror.  It's more like some bird feathers and butterfly wings, where it uses ridges or dots of clear material to achieve a colored effect.  The distance between the ridges interacts with the frequency of light to give you different colors.  The colors you're not seeing are the ones that the animal are what the animal actually sees.

Another question I had was, What does the phrase "eye of the tiger mean?"

I found out:

In the wild, seeing the "eyes" of the tiger signifies death, because right before a tiger attacks, it turns its ears forward so that the spot on the back of each ear faces nearer its prey. The "eye spots" on the back of tigers' ears serve to confuse predators and reduce the risk of attack from behind. Hence, once someone sees these "eyes", the tiger is about to attack.

Did you know:

  • Dogs and cats are color blind. They are said to be able to see only in pale shades of color.
  • Snakes have 2 sets of eyes. One pair for day and one pair for night.
  • Insects and bees use compound eyes made up of hundreds, even thousands of  tiny lenses placed together in a honeycomb pattern.
  • Horses eyes point sideways to give them excellent peripheral vision.


For more interesting information on animal eyes, visit the websites below:
Close-Up Photos of Animal and Human Eyes
How animals see the world
10 Most Incredible Eyes in the Animal Kingdom
Animal Eyes
Animal Eye Care

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