Detecting loss of sight in a cat can be difficult, because cats are so adaptable. If a cat loses sight over a long period of time, he has had time to adjust his behavior. He might even go about his business as usual, utilizing his other senses. If you suspect a change in your cat’s vision, testing his eyesight requires a combination of both observation and specific response tests.
Things You'll Need
- Cotton ball, torn
Observe the cat to determine if his behavior has changed. He may have vision problems if he is reluctant to jump down from heights, crouches low to the ground when walking or walks with his neck stretched out further than normal, allowing his whiskers to do more work.
Drop pieces of a torn cotton ball from a height of 4 feet next to the cat's head, to test his "tracking response." Cotton is used because it will not make noise as it falls. If the cat does not turn his head to watch the falling cotton, chances are his sight is weakened.
Shine a flashlight into and then away from the cat's eye. If the cat turns his head away, blinks or squints, this is called the "dazzle reflex" and indicates healthy eyesight. If the cat does not react to the light in any way, his eyesight is compromised.
Move your hand toward the cat's eyes in an abrupt, menacing way, but do not touch them. A cat with normal vision will react to this threat by thinking you are going to touch his eyes and he will blink. A cat with poor vision will not react.
Direct the flashlight beam into the cat's eye to see if the pupil constricts (gets smaller). This is called a pupillary light response. If the pupil does not react by narrowing, it doesn't necessarily mean there is problem with the cat's eyesight. However, it is an indicator that the cat might have health issues requiring medical attention.