Dog cataracts are a problem affecting countless dogs, especially as they grow older. Learn what this condition is, its potential consequences, and what you can do about.

What are Cataracts?

Similar to cameras, eyes have clear lenses in them that are used for focusing. A cataract is an opaque spot inside a lens. Such an opaque spot can be tiny (called an incipient cataract) and not interfere with functional vision. Or it can block more of the lens and cause some blurred vision (this is an immature cataract). Later on, the whole lense can become obscured by opacity, and that is when functional vision is lost (this is referred to as a mature cataract). Sometimes mature cataracts can change gradually and become hypermature cataracts. They are smaller in size because of loss of water and protein from the eye’s lens. That makes the lens shrivel and makes the lens capsule wrinle, like when a grape becomes a raisin. Some hypermature cataracts are highly cloudy, and others have some clear spaces that offer some vision if the eye as a whole remains functional. The process of transformation form mature cataract to hypermature catarac can extend from several months to several years, depending on the age and breed of your canine.

What are not cataracts?

All older dogs, from around 6 years old) start to get a hardening of their lens called “nuclear sclerosis” that makes the lens start to look gray in color. That gray or grayish-blue tone gets stronger as the dog gets older. If you see this, don’t panic because nuclear sclerosis has nothing to do with dog cataracts, and shouldn’t cause any vision problems.

Nuclear sclerosis also takes place in people, and in people it causes a reduction of near vision, which is why people often need reading glasses as they get older. But dogs have poor near vision to begin with, so there is no real decrease in their vision that comes with nuclear sclerosis.

Is it easy to tell the difference between dog nuclear sclerosis and dog cataract? You really can’t. You can get your family vet to check your dog’s eyes for an initial diagnosis, but it is often necessary to go to a dog opthamologist to get a clear diagnosis. They have special equipment and expertise that allows them to distinguish between the two. Of course there is always a possibility that geriatric dogs can develop both nuclear sclerosis and cataract.

Your geriatric dog’s eyes may appear cloudy without it hampering his vision. Don’t assume that this is not cataract. It could indeed be incipient cataract as discussed above, with so far only small opacities that don’t obscure full vision. Dogs also have a powerful ability to adapt and compensate for loss of vision in one eye or even in both. They can rely on the other eye for certain information if one eye has an opacity that obscures vision. Even if both eyes have moderately severe cataracts, dogs can adapt by developing a memory map of where things are in their environment, so their memory fills in the spaces that are obscured by opacities. So the dog’s owner may not even be aware that their dog’s vision is seriously impaired – that is, until it gets very serious in both eyes. But it is important to take action against cataracts before they get to this stage of development.