Why are my Dog's Eyes Cloudy Blue?
I recently noticed that my 7 year old Golden Retriever's eyes have a hazy blue tinge in bright sunlight. The haziness is most visible deep in the eye, in the pupil. Is this a problem? He still seems to see fine and he doesn't squint or rub his eyes.
San Leandro, CA
It probably is not a problem.
I suspect that your dog is developing a syndrome called nuclear (or lenticular) sclerosis. It occurs in all older dogs and cats.
As the eye ages, cells in the lens (which is located within the pupil, in the portion of the eye that looks somewhat deep when viewed from outside) die of old age. They are replaced by new cells, so the lens doesn't atrophy significantly. However, over time the remnants of the dead cells cause the lens to become mildly cloudy. The cloudiness is gradually progressive. In middle-aged dogs and cats, it may only be noticeable as a blue, smoky haziness within the eye in bright light. In very elderly animals, the syndrome is more pronounced: 22-year-old cats have lenses that are obviously grey and cloudy.
The accumulations of cell remnants are technically cataracts, but they're not dangerous cataracts. They are harmless. I never have seen nuclear sclerosis affect quality of life, longevity, or measurable visual acuity in any animal. I view the syndrome as a mark of distinction -- animals with nuclear sclerosis have been well cared for, allowing them to live to a mature age.
There are some syndromes, such as bona fide dangerous cataracts and inflammation of the cornea (the front portion of the eye) that might be confused with nuclear sclerosis by a pet owner. Therefore, any pet with visible changes to the eyes should see a vet immediately. Hopefully, the vet will find nothing to be worried about.