Tuesday, June 29, 2010

National "Camera Day"

Today, June 29th is National Camera Day.

I love great pet photos and it is great fun to take a perfect picture of your pet.

Do you know why your dog's eyes shine in such a creepy way in photos?

Ebony At Twelve Weeks Old

The answer is, for the same reasons our eyes come out red – because of the way the flash is reflected off the back of our eyes. The difference in color of the reflection is due to the structure of the eye. In a person, flash photography makes our eyes appear devilish red. This is because the flash reflects off the a blood vessel rich layer behind the retina.

In dogs (and many other animals), the retina has a reflective layer behind it called the tapetum lucidum. This layer acts like a mirror, reflecting light at the back of their eyes. The reflective layer is what helps dogs and cats see better at night. Light is reflected outward, giving the dog's retina a second chance to absorb the rays.

Light that is not absorbed exits the eye, appearing as the "eyeshine" seen in photos, from headlights, flashlights, etc. This ability comes at a price, as dogs cannot see detail as well as humans (they are more attuned to seeing motion).

Note: Some dogs lack pigment in their tapetum lucidum. In these individuals their "eyeshine" is red, as it is in humans.

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