Your dog’s vision is inherently different
than yours or mine. Human vision has evolved to offer sharp, narrow focus on
what's in front. Dogs have evolved a broader peripheral vision which lets them
pick up even slight movements all around them.
A dog’s vision is closely related to that
of a wolf. Domesticated dog breeds evolved from wolves many thousands of years
ago. While they are now a different species, they still share many common
Wolves' highly evolved vision allows them
to spot prey animals at long distances. Their vision also enables them to check
the movements of the rest of the pack while hunting in a group. Wolves hunt at
dawn and dusk. Along with a well-developed sense of smell, they have acute
vision even in very poor light.
Dog's Eyes vs Human's Eyes
Dogs have inherited many of these traits
from their wild cousins. They have wide, discriminatory vision and can see in
low light conditions. That's one reason they make such good guide dogs. They
can see what's going on all around them much better than even a sighted human can.
The breadth of a human field of vision is
about 180°. If humans want to look at things on either side or behind them,
they have to turn their heads and redirect their eyes. That's because human
eyes are close together at the front of the head. Dogs' eyes are more toward
the sides of the head. They have a breadth of field of between 250° and 260°
depending on the breed. Certain breeds with slender heads and small ears, such
as greyhounds, can see almost 360°.
Humans protect and clean their eyes by
blinking, but they have only one set of eyelids. Dogs have a third set like
birds and reptiles. It's called the "nictitating membrane" and it’s
practically invisible. The thin film of skin is pulled by a strip of cartilage
across the eye, side-to-side. It polishes and moistens a dog's eyes making sure
the animal's vision is always crystal clear.
For the advantage of broad peripheral
vision, dogs sacrifice focus. Most breeds cannot see fine detail much over 20
inches away. When they recognize their owners at a distance, it is by scent
more than by sight.
Clear Up Any Confusion
A popular misconception is that dogs are
color-blind. While their sense of color is not as distinct as that of humans,
they can see the entire color spectrum. But although they can see color,
research suggests that the color of an object is not as important to a dog as
it is to a human when it comes to identifying that object.
The most common threat to your dog’s vision
is from cataracts. Cataracts can develop at any stage of a dog’s life and are
usually age-related, diabetes-related or inherited. While surgery can be an effective
(but costly) correctional procedure, all surgery carries with it a measure of
risk. Fortunately, as dog lovers, you and I have a safe, effective and
completely natural alternative to the surgeon’s blade. Please consider our best-selling
herbal remedy, Cataractin, for cataracts in
Understanding the differences between your
vision and your dog's vision can help you better understand its behavior. The
special qualities of a dog's wolf-like vision and those of a human are an
excellent combination. In centuries past, these qualities made humans and dogs
the best of hunting companions. Today, they help guide those humans who are
poorly sighted. Next time you're out with your furry canine friend, think about
what it must be like to view the world through your dog's eyes.