Cataracts are, essentially, a loss of clarity in the lens of your dog’s eye. Cataracts start out as a minor clouding of the eye. As the condition progresses, your dog’s vision will become impaired and total blindness may result. A cataract may form rapidly in the course of just a few weeks, or slowly over a longer period of time. A cataract may occur in one or both eyes. Cataracts tend to develop in older dogs, but can be found in dogs of any age.

Cataracts will appear as a whitening in the central portion of the eye. Your dog's pupil(s) may also appear dilated. Be careful not to confuse the symptoms of cataracts with those of nuclear sclerosis, a condition frequently seen in older dogs in which the lens hardens and your dog’s eye appears blue or grey. Nuclear sclerosis, unlike cataracts, usually does not impact your dog’s vision.