What Is Happening When Your Dog's Eye Starts Turning Blue?

Regardless of the breed or the color of their coats, most dogs are born with dark-colored eyes. Sometimes, however, the eyes begin to change, taking on a distinctly bluish hue. A shift toward blue is rare in young pets but often occurs as dogs get older. The eyes are very efficient at creating new cells, but they aren't so good at getting rid of old ones. As the old cells build up in the lens, the lens becomes quite dense. This condition, called nuclear sclerosis, has little effect on vision, but it does cause the pupils to become slightly blue.

Another condition that may change the color of the eye - and which can have a serious effect on vision, sometimes causing blindness - is cataracts. Caused by a hardening of the lens, cataracts may result in blue, bluish white, gray, or even cloudy eyes. Pets with diabetes are particularly prone to cataracts, although they are common in healthy older pets as well.

A condition called glaucoma, which increases pressure within the eyeball, can also cause the eyes to turn blue. Glaucoma is often painful and can damage your dog's vision if it is not treated quickly. One clue to look for is a layer of blue across the surface of the eye that obscures the pupil underneath.

The color of your dog's eyes is also influenced by the amount of tears they produce. It is common for the eyes to become somewhat drier with the passing years. Declining tear production may cause the eyes to reflect light differently, resulting in a bluish color in the cornea (the surface of the eye). If one eye has turned slightly blue, and your dog is also squinting or has bloodshot eyes, there is a good chance that he has a scratch on the cornea.

Eye problems can be difficult to diagnose on your own, and you don't want to take chances with your dog's sight. So it is important to see your vet if there is suddenly a sign of blue. Most of the time, however, there won't be anything to worry about. Even if there is a problem, dogs don't depend on vision to the same extent that people do because they compensate with their other senses. Pets with dimming or even lost vision do remarkably well.

Pets with failing vision may get disoriented, however. That is why vets recommend trying to keep their surroundings as constant as you possibly can by not moving the furniture too often, for example, and being sure to pick things up off the floor before they stumble into them. It is especially important to keep objects off the stairs, which could cause your pet to take a hard fall. The eyes are surprisingly hardy, and corneal scratches will usually heal nicely on their own, says. But scratches can make the eye sore and sensitive to light, so you may want to pick up a sun-blocking visor at the pet supply store.

When visiting the vet, it probably won't take her more than a few minutes to figure out what is making your pet's eyes blue. Eye exams can be somewhat uncomfortable, however, so she may put in anesthetic drops to keep your pet more comfortable. She may also use drops that stain the surface of the eye, which will show if a scratch is present. If your pet does have a corneal scratch, your vet may use antibiotic drops to prevent infection.