Cataracts in cats are an eye condition that affects the transparency of the lens—the eye’s natural lens—leading to partial or complete vision loss. Although cats develop cataracts much less frequently than dogs, many felines experience disruptions to their lives due to this condition.
What Is the Lens and What Are Cataracts?
A cat's eye is similar to a camera, where different optical structures such as the cornea and lens act like the camera’s lenses, and a tissue that captures images—called the retina—functions like the camera sensor.
The lens is a biconvex structure located behind the pupil and is essential for accurately focusing light onto the retina, allowing the cat to see clearly.
Cataracts are an ophthalmic issue that affects the lens of the eye, creating a fog-like effect. This condition involves the gradual loss of transparency of the lens, which sits behind the iris and is responsible for focusing vision. As the lens becomes clouded—turning whitish or bluish—less light reaches the retina, and as the lens becomes more opaque, the cat’s vision deteriorates and sensitivity to light increases. This cloudiness occurs when the lens fibers become misaligned due to tissue disruption.
What Causes Cataracts?
Unlike in dogs, the most common cause of cataracts in cats is not hereditary. However, some hereditary cataracts have been reported in Persians, Birmans, and Bengals. Certain diseases, such as diabetes, can also cause cataracts in cats, though this is much rarer than in diabetic dogs.
By far, the main cause of cataract development in cats is intraocular inflammation. When there is internal eye inflammation (uveitis), substances are released that disrupt the lens’s nutrition, potentially leading to cloudiness. Unfortunately, uveitis is fairly common in cats. It is sometimes linked to viral diseases (such as leukemia, immunodeficiency, FIP, or herpes) but can also result from bacterial or protozoal infections (such as leishmaniasis).
While cataracts are more common in older cats, younger cats can also be affected.
How Can We Identify Cataracts?
Cataracts may develop suddenly or gradually over time. Often, you might notice a change in the color or appearance of your cat’s eyes—where the pupil may appear whitish or cloudy. This color change is most noticeable in low-light conditions when the pupil dilates and exposes more of the lens.
Sometimes, before the color change is obvious, you may notice your cat struggling to judge distances when jumping, avoiding areas they used to climb, or knocking over objects they previously avoided easily.
When cataracts develop due to severe eye inflammation, the eyes may appear red, cause discomfort, and prompt frequent eye rubbing or squinting.
Main Symptoms to Watch For:
How Are Cataracts Diagnosed?
If you suspect your cat may have cataracts, it’s important to seek veterinary care for an accurate diagnosis. The veterinarian will perform a complete ophthalmological exam using a slit lamp to assess the degree of lens involvement and ocular inflammation. Measuring intraocular pressure is essential to determine whether the inflammation is hypertensive and to choose the right medical treatment. Your vet may also recommend general diagnostic tests to identify the cause of the uveitis.
Is There a Treatment?
As with dogs, there is no effective medical treatment for cataracts in cats. Once formed, they can only be removed surgically. The procedure is similar to that performed in dogs and involves removing the lens via phacoemulsification and replacing it with an intraocular lens.
If the cataract is mature and obscures a direct view of the retina, an ultrasound and electroretinogram are performed to confirm that the retina is functioning properly and is not detached.
After surgery, anti-inflammatory treatment is important, and regular veterinary check-ups during the first few weeks are essential. Post-surgical success rates exceed 90% when the underlying causes of the cataract have been managed.
Cataracts in cats are an eye condition that can significantly affect a pet’s quality of life if not properly diagnosed and treated. At IVeM, we recommend careful observation of symptoms, prompt veterinary care, and surgical intervention when necessary to manage the condition and preserve your cat’s vision.
