Q: I have been told by many people that all-white, blue-eyed cats will usually go blind at an early age. As the owner of a wonderful blue-eyed, white cat (seven years old), I am concerned. Is there any truth to this, or is it an old wives' tale? (I hope it is.)

A: Blue-eyed, white cats are not more prone to blindness - either hereditary or acquired - than other cats. Your friends may be confusing blindness with deafness: here, the situation is completely different. Hereditary deafness is a major concern in white cats, and even more so if one or both irises are blue in color.

Researchers found that only 17 to 22 percent of white cats with non-blue eyes are born deaf. The percentage rises to 40 percent if the cat has one blue eye, while upwards of 65 to 85 percent of all-white cats with both eyes blue are deaf. Some of these cats are deaf in only one ear. Interestingly, if a white cat with one blue eye is deaf in only one ear, that ear will invariably be on the same side of the head as the blue eye.

Cats with just one deaf ear may appear perfectly normal, and their problem may never become known to their human companions. Even cats that are totally deaf from birth can make perfectly satisfactory companions as long as a few precautions are heeded. Try to keep them out of situations where their safety depends upon their ability to pick up auditory cues. Don't let them go outside where they can be killed or injured by threats they cannot hear, like from roaming dogs and speeding cars. There is no treatment for hereditary deafness.