Blindness in Cats

Blindness in cats is not a common condition, but it is one can be caused when underlying conditions are allowed to progress without treatment. Because cats do not necessarily need both eyes to see clearly, it can sometimes pose problems when trying to determine if your cat has lost sight. They use their other senses, such as touch, smell and sound very well and can usually navigate quite well, even with a total loss of vision.

Causes of Blindness in Cats

Blindness in cats can be either sudden, when some type of trauma or sudden illness causes the loss of vision, or it can be a deterioration of the eyes over time. An unknown or untreated underlying condition is usually responsible for the decrease in sight capabilities over time. Conditions such as glaucoma, high blood pressure and tumors are the leading causes of blindness in cats.

Glaucoma is the most common cause of blindness in cats. It occurs when there is a build-up of pressure in the eye socket, leading to damage of the ocular nerve. When the ocular nerve becomes damaged, sight messages can no longer be interpreted correctly and the loss of sight occurs.

High blood pressure can cause blindness if left untreated for too long. Increased pressure in the capillaries, or blood vessels, of the eye can cause destruction of the retina. The excessive pressure causes the capillaries to burst, leaving your cat with a bloodshot appearance of the eyes. This is usually what helps the owner realize that there is a problem.

Severe damage to the eyes is also a possible cause of blindness. Most of the time this occurs in outside cats, because they are more commonly involved in fighting. Scratching or biting can cause critical portions of the eye to be destroyed. Not only can destruction of the eye be harmful, but infection that sets into the open wound can also lead to blindness.

The most serious cause of blindness is tumors. Tumors that lodge themselves in the brain or the sockets of the eye can apply pressure to critical systems which are depended upon to relay the message of sight. When tumors affect the brain, the occipital cortex is usually damaged and there is no hope for the return of sight. Likewise, when there are tumors lodged against the eye, pressure applied to the retina and ocular nerve causes permanent damage.

Signs of Blindness

It can sometimes be difficult to determine if your cat has lost his sight. Some of the signs to be aware of include:

  • Bumping into things
  • Jumpy behavior, appearing startled
  • Loss of interest in normal activities

Diagnosing Blindness

Diagnosis is directly related to the cause. However, in order to determine if blindness is present and the actual cause of it, a variety of tests need to be performed. Testing can include any of the following:

  • Thorough examination of the eyes with light
  • Testing the reflexes of the pupils
  • Physical observation of the cat's walking habits

Testing can also include an examination of the nerve and brain functions if tumors are suspected.

Treatment of Blindness in Cats

Treating blindness will be different in each case, depending upon its cause. Glaucoma and high blood pressure need to be treated independently. However, if the condition has gone untreated for too long, it's likely that there is permanent damage to the structures of the eye and blindness is irreversible. The condition will still need to be treated to avoid dysfunction of other important functions.

If tumors are present, they will need to be removed surgically. If the tumors have caused permanent damage to the structures of the eye or the nerves in the brain, blindness may be irreversible.