Does your dog have cloudy eyes?

I'm often asked if older dogs with cloudy eyes have cataracts, and the answer is: not always. Let's look at the difference between a cataract and a condition that dogs develop with age, known as nuclear sclerosis of the lens.

Nuclear sclerosis (also known as lenticular sclerosis) is a normal, age-related change in the lens of the eye. It's characterized by a bluish-gray, cloudy appearance in the center of the eye. While it may look similar to a cataract at first glance, it's a physiological process of aging, not a disease.

Key fact: Nuclear sclerosis does not cause blindness. Light can still pass through the lens to the retina, allowing the dog to maintain functional vision.

Why does this happen?

Let's begin by learning about the anatomy of a dog's eye: the eye is composed by two chambers: the anterior chamber, located between the iris - the colored part of the eye, and the cornea, the outer, transparent layer. The anterior chamber is filled with a fluid called aqueous humor, which nourishes the cornea and maintains the eye's internal pressure.

The other lens is called the crystalline lens, and it adjusts to allow the dog to see near or far. This adjustment is achieved thanks to fibers in the crystalline lens.

A dog's crystalline lens continues to produce new fibers throughout its life. Because the outer capsule of the lens has a fixed size, the oldest fibers are pushed toward the center (the nucleus). Over time, these central fibers become compressed and dehydrated, increasing their density and creating the blurred reflection we observe.

Handling and care

This condition does not require surgery, as vision is preserved, and there is no medical or surgical indication to remove the sclerosis. Regular eye exams (every 6 to 12 months) are recommended to prevent the development of cataracts with age.

Specialized eye supplements can be used to support the overall health of the retina and lens. Consult your veterinarian to find the best options.

More information can be found here:

• VCA Animal Hospitals: Lenticular Sclerosis in Dogs

• Veterinary Partner (VIN): Cataracts and Nuclear Sclerosis

• ACVO (Specialists): Age-Related Changes in the Eye