Dog Vision

Dog vision - what do our friends see?

There are some common misconceptions in the canine-lover's world about how well dogs see.

In fact, for their purpose, dog's have quite useful optical tools at their disposal. While it is true dogs usually depend more on their sense of smell, evolution has provided them with some quite complimentary eye-sight.

A myth: Dogs are color-blind....not!

It is a common to hear people say dogs are color blind, and that simply is not true.

What is true is that dogs eyes have only two cones each, whereas the human eye has three. Thus, dogs are "dichromatic" while you and I are "trichromatic".

Here is a nice comparison of the color spectrums visable to humans and dogs:

Basically this means that dogs cannot see green or probably red. But they can still see violet, indigo or blue. So a dog has difficulty differentiating between objects that we see as, green, orange, yellow or red.

Think about that when you choose which color ball to toss to pooch in the back yard. He's going to have problems finding a red ball that has found it's way into long green grass!

Interestingly, however, the fact that dogs are dichromatic makes them much more sensitive to different hues of grey, meaning they can see much better than we do at night or near night.

So don't feel so bad for him.

On the left is a picture of the way we would view the puppy, and on the right, how the same picture would look to a dog:

Read more about dog color blindness (or lack thereof), here.

Dog eye reflection

Speaking of seeing at night, the "shiny eyes" you see whenerver you take a doggie picture at a certain angle, or if you see other light reflected into a dogs eyes at night, may be the result of another evolutionary phenomena that allows a dog to see better in near darkness.

The back of the dog's eye (choroidin) has a shiny layer called the tapetum, that reflects the dog's vision back to the rods up front, and are thought to help with night vision by doing a better job of "capturing" any available light.

In most dogs (for example, non-white Boxers), the reflection is silver to bluish-green. However, in dogs with very little pigment in the iris such as blue-eyed and fair hair colored dogs, this reflection bounces back an eerie, devilish red. This is because the pigment in the eye isn't dark enough, and what you are seeing is actually the light being reflected through the bood vessels in the iris.

Field of Vision

One characteristic of vision in which our canine friends excel is range of vision. It is hard to get something past the "corner of a dogs eye'.

Humans generally have a 180 degree panoramic view. But dogs, depending upon the shape of the breed's head can view an amazing 270 degrees of the 360 degree full circle at any one time.

Boxers, due to their head shape have one of the dog-world's smallest fields of vision. They are able to see only 220 to 240 degrees at a time.

Dog Vision Distance

The dog's eye is set up to see moving things clearly, while our vision is generally better when we train our eyes on a fixed object.

A dog can easily see an object over a half mile distant, if it is moving, but has trouble seeing things more than 600 yards away, if they are stationary.

Close up, things less than a yard a way may look blurry to a dog.

On a human scale,average dogs would have '20/75'rating. That is, what a human would see at 75 feet, a dog would see as clearly at only 20.

In summary, Dog Vision isn't its strong suit, but it is well adapted to the animal's specific needs.

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