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Pantops Pet Salon & Spa
Charlottesville's Professional Dog Grooming

It's what we do -- it's all we do.

(434) 293-2424
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504 Pantops Center
Charlottesville, VA 22911

The Sense of Sight

Thursday, January 18th, 2007 by Mike Cronk

Through educating ourselves about the five senses in dogs compared to our human capabilities, we develop a much greater understanding of the world our canine companions experience.  Sight is our bag!  Our visual system has a greater portion of the brain devoted to it than to any of our other senses—not true for dogs.  The amount of light taken in by the pupil and the amount of the light interpreting structures within the eye (cones and rods) are markedly different between man and dog.  Since dogs originally were active hunters during dawn and dusk, they are more sensitive to levels of brightness but their ability to perceive color falls by the wayside.  When compared to other animals, though, the dog has relatively good vision.  Based on current research, here is what we know:

 

1.  Dogs have larger pupils and more light interpreting rods than humans, giving them superior night vision.  It is estimated that dogs need ¼ the amount of light that humans do to see at night—cats, 1/7.

2.  Human eyes focus better than dog eyes.  We can pinpoint an object in the distance and then easily switch to looking at an object close-up.

3.  Dogs have better side to side vision enabling them to follow prey on the horizon.  Horses and antelope have the same capability, allowing them to scan for predators better.

4.  An object that can barely be seen by a dog at 20 feet can be seen by the person with normal vision (or corrective lenses) at 75 feet.  While our visual acuity is 20/20, that of dogs is 20/75 –much worse.  The standard driver’s license requires less than 20/40—meaning most of our dogs would have to wear glasses in order to drive legally!

5.  Dogs have superior motion sensitivity.  If an object 900 meters away is stationary, they can’t recognize it but once it moves they not only can see it, but identify it as well.  Greyhounds can identify their owner when in motion, as much as a mile away!  Yet, if the owner is standing still at 100 meters, they become invisible to the dog.
6.  Because an average dog’s eyes are set more on the sides of the head, their field of vision is about 240 degrees compared to 200 in man (yes, Pekes and Pugs are the exception).

7.  Dogs are not color blind, but the colors they see are not as rich or varied as those seen by man.  The latest research claims the following:  “instead of seeing the rainbow as violet, blue, blue-green, green, yellow, orange, and red, dogs would see it as dark blue, light blue, grey, light yellow, brown, and very dark grey.  In other words, dogs would see the colors of the world as basically yellow and blue.  They see the colors green, yellow, and orange as yellowish and they see violet and blue as blue.  Blue-green is then grey.  Red is difficult for dogs to see and may register with them as dark grey or perhaps even black.”  So much for the variety of color in dog food!

We have to be careful about generalizations with regard to the senses.  Always keep in mind that the ancestor of the dog, the wolf, has evolved into a variety of breeds today through controlled breeding by man.  Therefore, sight hounds have better vision and scent hounds are more adept at sniffing things out.

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