Effects of Cataracts – From the Cat’s Point of View
The term “cataract” refers to any opacity or cloudiness of the lens of the eye, regardless of its size. Cats of either gender can develop cataracts for a number of different reasons, although in cats most reported cases have been congenital. The symptoms of feline cataracts are the same, regardless of their cause. Some cats with cataracts act completely normal and don’t seem to suffer any adverse consequences or show any signs of decreased vision, especially if only one eye is affected. In advanced cases, most cats do experience vision deficits, which can progress to actual blindness. Sometimes cataracts are irritating and can even become painful.
Symptoms of Cataracts in Cats – What the Owner Sees
The main visible sign of a cataract is an icy blue spot or cloudiness that develops on the lens in the pupil of the cat’s eye. The cloudy spot may start and stay small or get bigger gradually over time. Sometimes, cataracts spread quickly to cover most or all of the pupil. The chief complaints by owners of cat with cataracts are that they notice cloudy spots in their pet’s eyes and changes in its vision. Cataracts can develop in one eye or in both. Many cats have cataracts from the time they are born. Abnormalities that are present at birth are called “congenital” disorders. Depending on the severity of the cataracts, affected cats can display a variety of vision problems, ranging from mild impairment to total blindness. Owners of cats with cataracts may notice one or more of the following signs that are associated with impaired vision:
- Cloudy spots in the pupil of one or both eyes; may look like an ice-blue chip
- Unusual high-stepping walk; abnormal ambulation
- Unsure footing
- Tripping over or bumping into familiar objects (walls, furniture)
- Misjudging distances
- Not recognizing familiar people
- Watery eyes
- Changes in eye color
- Changes in pupil size or shape
Cats at Increased Risk
Certain breeds are predisposed to developing cataracts, including Persians, Birmans, Himalayans and Domestic Shorthairs. This is undoubtedly due to hereditary factors. Cats can develop a condition called nuclear sclerosis, which also causes a cloudy bluish haze on the lens. It is caused by normal aging of the eyes as cats get older; the lenses lose their ability to retain water and fibers build up on the lens’ surfaces. Owners may confuse this condition with cataracts. However, nuclear sclerosis normally does not impair a cat’s vision and doesn’t require treatment.