As I progress through my series on aging pets, I will stop again on a commonly misunderstood yet scary condition that happens in pets. This is the changing of the eyes that makes them white. In people, the most common condition causing this is cataracts. Considering this could mean serious problems for vision and other health issues, owners become understandably concerned when they see the possibility of this starting in their pets. The good news is what people see at home isn’t usually cataracts at all.
The lens of the eye is not much different than an artificial lens outside of the body. It is basically a complex “crystal” that is used to focus light in a certain way so that the eye can focus and discern objects and surroundings. As an organic structure, it is made of fibers and proteins instead of minerals. However, “flaws” in the lens will appear the same as flaws in a gemstone. There will be facets visible that reflect and refract light in different directions. The more flaws, the more opaque the crystal becomes. This is the basis for actual cataracts. The lens gradually becomes full of these little micro-flaws until it becomes white. The most common cause of this is diabetes. Like in people, diabetes causes the blood sugar to rise in the bloodstream. When this reaches a certain point, sugar can start to leach into the eye and lens, throwing off the fine latticework of the lens. However, we can also see it as a genetic disease in some breeds without diabetes. While poorly understood, dog breeds like Bichons, Fox terriers, and Boston terriers will develop cataracts without an underlying disease. The same can happen in certain cats like British Shorthairs and Himalayans. Regardless of cause, cataracts are as scary in pets as in people. It causes vision loss and can progress to other eye issues unless expensive surgery is performed.
MUCH more common than cataracts in dogs and cats is a condition called nuclear (…or lenticular) sclerosis. The lens of the eye is actually always in a state of change throughout our lives and the lives of our pets. Specifically, it is getting denser and denser with age. A normal, younger lens is capable of flexing and stretching to help focus. But, as it gets harder, it starts to get fixed in its most common state. In humans, that state is to focus on things that are far away. As a result, when we hit our forties, we need reading glasses to compensate. This is the same in pets. However, the aging process is so much faster in pets (7 dog years to our 1…), the lens can’t keep up and starts to become cloudy. But, while cataracts require veterinary intervention, this other, benign condition just means that your pet’s up-close vision just won’t be what it used to be.
There are distinct differences between these two conditions that vets use to determine how worried we should be. That said, I have trained enough budding young vets to know that, while distinct, it does take experience to determine why a pet’s lens is cloudy. If you are seeing your pet’s eyes getting cloudy, let your vet take a peek to make sure it’s not something serious. As with anything, early intervention will have the best outcome.