What Causes Cloudy Eyes in Cats?
Problems with a cat's outer eye are usually one of two common ailments: conjunctivitis and cloudy eye.
- Conjunctivitis is an inflammation of the lining membrane that covers the inner sides of the eyelids as well as the eyeball's surface up to the lid. Conjunctivitis is one of the most common eye problems among felines.
- Eye cloudiness is a different problem. It is usually caused by one of four things: keratitis, glaucoma, cataracts, or a corneal abrasion.
Whatever the cause, cloudy eye should be treated very seriously. Make an appointment with your vet. Meanwhile, let's find out more about these very different types of eye problems that can cause a cat's eyes to become cloudy or hazy in appearance.
What Is Keratitis?
When a cat's eyes become cloudy, the area can be minute, appearing as a small localized haziness, or it can make the complete eye seem opaque. In this opaque situation, the inner eye structures are not visible.
Keratitis is an inflammation of the cornea or clear part of the front of the cats eye. There is a loss of transparency of the cornea. At first the cornea appears dull, later hazy, then cloudy, and finally it will be covered by a whitish-blue film. In late stages there is a deposit of black pigment on the cornea, which blocks out light. Keratitis is always considered serious because it may lead to partial or complete blindness.
How Is it Different from Conjunctivitis?
Superficial or surface keratitis is often confused with conjunctivitis. It is extremely important that a veterinarian examine the animal to distinguish between the two, so that the cat receives the proper treatment. Keratitis is an extremely painful condition accompanied by excessive tearing, squinting and sensitivity to light. The third eyelid comes out to protect the eye. Conjunctivitis, on the other hand, is characterized by chronic discharge but very little pain.
Infectious keratitis occurs when a corneal injury becomes infected. A pus or mucus-like discharge runs from the eye and the lids are swollen. Several kinds of bacteria cause infectious keratitis. Cultures, along with the appropriate antibiotics, will be required.
What Is Glaucoma?
Glaucoma, or "hard eye," develops due to an increase in fluid pressure within the eyeball. When eye pressure reaches a point that is greater than the arterial blood pressure, arterial blood can not enter the eye to nourish the retina. A cat suffering from acute glaucoma will have extremely tender eyes and has a fixed blank look due to the hazy and steamy appearance of the cornea and the dilated pupil. If you gently press against the eye with your index finger through the eyelid, the affected eye feels harder than the normal one. Any excessive tearing and squinting is a response to pain. If chronic glaucoma remains untreated, the result will be an increase size of the eye and protrusion.
Glaucoma can be diagnosed by measuring intraocular pressure with an instrument placed on the surface of the eye and by inspecting the eye's interior. Some permanant vision may already be lost before the disease is even discovered. Chronic glaucoma may be managed for a time with drops and medication.
What Are Cataracts?
Cataracts are rare in cats. They are defined as any opacity on the lens which interferes with transmission of light to the retina. A spot on the lens that blocks out light, regardless of its size, is technically a cataract. Cataracts usually appear after conjunctivitis, an eye injury, or infection. They also may develop later in life in cats that are diabetic.
How Long Do Corneal Abrasions Take to Heal?
Another possible cause of hazy or cloudy eyes is a corneal abrasion. These eye injuries are usually caused by a scratch, but can also be a result of a misdirected eyelash or other foreign object in the eye. They are extremely painful. The cat often squints, waters, paws at his eye, and light may hurt his eyes. Often the third eyelid comes out to protect the injured eye. If the injury is extensive, the surface of the cornea immediately surrounding the injury becomes swollen, giving it a hazy or cloudy look.
Healing usually takes place within 24 to 48 hours, but not if a foreign object is still imbedded in the cornea or beneath one of the eyelids. If the abrasion is mild, no exam may be necessary. Otherwise, have a vet check for foreign bodies under the eyelids. Any delay in identifying that as the problem could lead to a persistent corneal defect (ulcer) or inflammation of the cornea (keratitis).
References: The Cat Owner's Home Veterinary Handbook, by Delbert G. Carlson, D.V.M and James M. Giffin, M.D., First Edition