Why Don’t Cats Blink?
Yes, they do, but not the way humans do.
Cats, unlike humans, do not need to blink their eyes regularly. Human eyes need to blink at very frequent intervals to keep them lubricated, but cat’s eyes don’t require this constant wetting with tears. It would make sense that cat’s eyes evolved to work this way as less frequent blinking should improve their hunting abilities.
The cat’s third eyelid (or nictitating membrane) which moves horizontally across the eye from the inside to outside, helps to keep the eye lubricated.
The nictitating membrane is a thin, translucent or transparent third eyelid found on birds, fish, reptiles, and amphibians, as well as some mammals. Some animals, like many species of birds, have full active muscular control over their nictitating membranes and can move or blink them at will like we close our eyelids. They do so to moisten their eyes, or to clear debris. The cat’s nictitating membrane contains less muscle fibres, so cats don’t have the ability to blink their third eyelid at will.
This third eyelid is not usually visible, but you can sometimes spot it if a sleeping cat slowly cracks an eye open to take a look at what’s happening around him. For cats, having the nictitating membrane extended and visible while the eye is open is usually a sign of illness or a problem with the eye.
The long whiskers above cat’s eyes are there to protect the eye from damage. When one of these senstive whiskers comes in contact with anything it triggers a blink reflex – an automatic and involuntary closing of the eyelids, protecting the cat’s eyes from possible danger. You can see this in action by simply touching one of these whiskers and watching your cat blink.