Causes of Sudden Blindness in Cats

Blindness can occur suddenly in your cat, and the cat can show different signs such as bumping into furniture and dilated pupils that remain the same even in the light. Vision loss may have various causes that can include high blood pressure, diabetes, heart or kidney problems.


Hypertension or high blood pressure can cause sudden vision loss in felines. This is the most common cause of blindness and is more frequent in senior cats. Hypertension may be caused by an underlying condition.

The high blood pressure causes retinal detachment, so the cat will no longer be able to see.


Diabetes is a condition that is caused by high glucose in the blood and if left untreated, the cat may lose his vision.

The cat should receive insulin shots, so that the diabetes is fully under control.

Thyroid Problems

Thyroid problems can cause high blood pressure and high glucose in the blood, so sudden blindness can occur in cats with thyroid hormones in excess (hyperthyroidism).

Kidney or Heart Disease

Kidney or heart disease may cause hypertension or high blood pressure and this will lead to sudden blindness. It is important to detect any underlying conditions so as to be able to offer suitable treatment.

Medication Side Effects

Certain medications such as Baytril, which is used to eliminate infections, may cause sudden blindness. This side effect is rare, but if it occurs, the blindness is irreversible.

Detect Sudden Blindness in Cats

A blind cat will be less active and will often bump into furniture, especially if the loss of vision is recent.

If you suspect your cat may be blind, you should perform a few tests. Get a flashlight and dim the lights, then point the flashlight close to the cat’s eyes. If the pupils shrink, this means that your cat is not blind; if the pupils stay dilated your cat has probably lost his eye sight.

Another test you can perform is to drop a piece of paper or a soft object in the cat’s face and see if he responds in any way; the normal response would be blinking. If your cat fails to blink, you should consult a vet.

Sudden Blindness Prognosis

Sudden blindness or retinal detachment can be reversible if it is detected in a timely manner. The only scenario the blindness is permanent is if this occurs after the administration of Baytril.

The underlying condition causing the sudden loss of vision should be treated. The high blood pressure should be controlled with proper medication (i.e. Norbasc or Amlodipine). The sooner the blood pressure is normalized, the higher chances of the cat regaining his sight. You should get your pet as soon as you notice he has vision problems. In some cases, if the cat has been blind for several days, the retina may not be reattached.

Cats with diabetes should receive periodical insulin shots and should also lose some weight.