Your Dog's Eyes

Unless you were born blind, you already know how valuable your eyes and vision are in coping with life. Helping you to process information on the world around you, your eyes constantly work to help you enjoy life and avoid danger.

Dogs also use their eyes in similar ways, but with a few minor important differences. People see far and near fine detail in a wide range of colors and shades. Dogs however, even sight hounds which have good vision, have a poorer color range and they are much better at detecting movement than detail. This gives them an advantage with night vision, but they are poorer at seeing fine or close detail. The main advantage dogs have is that they don't have to rely purely on vision for information on their world. An acute sense of smell and excellent hearing, along with good motion sensing vision, means that dogs sense much more of their surroundings than mere humans. This extended sensory ability made them ideal companions to early man, when danger lurked around every corner.

Dog's eyes even look remarkably similar to human eyes. Like people, dogs have a range of eye colors although their predominant color is brown. One important difference between dogs and humans is that dogs have a third eyelid called a nictitating membrane. Although this membrane is not easily seen, certain diseases and eye irritation can make it stand out. The third eyelid sits in the inside corner of a dog’s eye and helps to protect it from irritation by cleansing and lubricating the eye.

Most of the eye diseases and problems seen in dogs are the same as those found in humans. One of the most common problems seen in dogs is due to simple eye irritation. The same environmental irritants that affect people also affect dogs. Dust, smoke and chemical pollution are the common causes of watery, irritable eyes in your favorite pets. Apart from seeing red, teary eyes which are often swollen, you will likely observe your dog rubbing or scratching at his eyes. Look carefully at whether both or only one eye is irritated. Symptoms occurring in only one eye usually mean a foreign body or injury in the eye involved.

Blocked tear ducts can also produce excessively watery eyes in dogs as well as humans. In some dog breeds, such as older Poodles and Shih Tzu's, you will often see damp and matted fur around their eyes and that signals possible tear duct blockage. An expert opinion from a veterinarian is often needed to tell the difference between the various causes of watery eyes.

Another trait that elderly dogs share with elderly humans is the development of cataracts. Most long term dog owners have seen the cloudy, milky haze that spreads in the center of each pupil as the cataracts form. This milky haze is the lens inside your dog’s eye becoming opaque and the dog slowly going blind. It's important to distinguish cataracts from another change called Lenticular Sclerosis. Lenticular Sclerosis is a condition which looks similar to cataracts but where only the center of the dog’s lens hardens and vision remains unaffected. Both problems are seen in elderly dogs.

One significant advantage that aging dogs have compared to humans is that eye damage and blindness does not incapacitate them to the same extent as human blindness. Good hearing and an acute sense of smell compensate well. There are many stories of blind dogs managing wonderfully well in life and it's a pity aging humans are unable to see through the "eyes" of their beloved dogs at times!

Until next time,

Teia