Dogs’ eye anatomy is very similar to ours. The most important structure for vision in both people and dogs is the retina, a membrane located at the back of the eye. The retina consists of hundreds of thousands of cells that are responsible for generating the images we see. Here are some different characteristics of dogs’ vision and how they can change from breed to breed.
Dogs have “low-resolution vision” when compared to humans. This means that when a dog sees an image, it appears less sharp than it would to us. This is because dogs have fewer cone cells, the cells in the retina that help make images sharp, than people do.
Night Vision and Motion Detection
Though dogs may not see objects clearly, they make up for it in other ways. Dogs’ night vision and motion detection are far superior to humans’. This advantage exists because dogs have a higher proportion of rods, the specialized cells responsible for night vision, motion detection and peripheral vision in the retina.
Nearsightedness and Farsightedness
We haven’t yet convinced our patients to read eye charts, but at one time, it was assumed that all dogs were nearsighted, which means distant objects always appear blurry. But new information suggests that this may not be the case.
Some breeds, including Schnauzers, Collies, Toy Poodles, English Springer Spaniels and Rottweilers, appear to have a higher risk for nearsightedness. One study found that nearsightedness increases with age in all breeds.
Nearsightedness explains training frustrations when your dog is a good distance away and looks rather confused when you give the command to come. When a dog stops and stares, it generally means they’ve lost their focal point.
Some breeds, like Australian Shepherds and Bouvier des Flandres, tend to be more farsighted, meaning objects up close are blurred.
Seeing in Color
Dogs do see in color, but the range of colors they can see is limited compared to ours. Humans have three types of color-detecting cells called cones, which allow us to see a wide range of colors. Dogs’ eyes only have two types of cones. So dogs can see colors, but they have trouble differentiating between red and green, similar to people with color blindness.
Dogs’ eyes are placed more to the side of the head than humans’ are, which gives them the ability to see a broader view, a wider angle of vision, but less field of depth. Because there is minimal visual overlap, your dog will easily catch a ball moving sideways, but may miss the ball if it’s tossed right at his nose.
Dogs are extremely adaptable to any type of vision impairment, including blindness. Often, our clients are not even aware that their dog has become blind until the furniture is rearranged and Fido has to learn the new arrangement!
Don’t assume blindness can’t be corrected. Cataracts, a common cause of blindness, can be surgically treated. Other problems, such as inflammatory conditions and high blood pressure, can be treated, too, possibly restoring vision.
It’s always a good idea to have your dog’s eyes checked during annual examinations.
A Dog’s World
While dogs don’t see the world as clearly or as colorfully as we do, dogs rely far less on their vision than humans do. The canine nose and ears provide far more sensory input. Dogs perceive smells long before we do and can often detect smells we don’t even know are present. And dogs perceive a tremendous range of sounds that we can only imagine.
If you’d like to learn more about your dog’s vision, schedule an appointment at I-20 Animal Medical Center.