Blinking

Blinking is a natural and involuntary action of opening and closing the eyelids rapidly. It is a regular and automatic process that helps protect and lubricate the eyes. When we blink, the eyelids sweep across the surface of the eyes, spreading tears and removing debris or irritants that may be present.

Wikipedia

Blinking keeps eyes safe from potentially damaging stimuli, such as bright lights and foreign bodies like dust.

Women blink nearly twice as much as men.

A blink lasts approximately three seconds.

The normal rate of blinking is 15-20 times a minute. However people blink less while lying, and up to eight times faster than usual afterwards.

You blink about 84,000,000 times a year.

Our eyes are closed for roughly 10% of our waking hours overall because we blink so much.

If all the time our eyes are shut when blinking is added together, we would spend 1.2 years of our waking lives in pitch darkness.

In The Silence of the Lambs , Hannibal Lector (Anthony Hopkins ) only blinks about 15 times in the entire movie. This is a technique that Hopkins used to make Lecter seem more unsettling and menacing.

In an interview with Barbara Walters, Hopkins explained that he learned the technique from watching other actors, such as Laurence Olivier. He said that not blinking makes you seem more "still" and "powerful." It also makes you seem like you're not afraid to stare people down, which is something that Lecter is very good at.

The average computer user only blinks seven times a minute when in front of their screen.

Most animals blink. However, some animals such as fish and snakes live in environments where there is not a lot of dust or debris, and their eyes are protected by their scales or membranes. 

Blinking can actually be harmful to fish. If a fish blinks, it can accidentally suck water into its eye, which can cause infection.

Most mammals blink with their upper and lower eyelids. The frequency of blinking varies depending on the species, but most mammals blink about 15-20 times per minute.

Cats slow blink as a sign of affection and trust. They do this by closing their eyes slowly and partially, often while narrowing their pupils. This behavior is similar to how humans smile, and it is thought to be a way for cats to show that they are feeling relaxed and content.

Birds have a third eyelid called a nictitating membrane that slides across the eye to protect it. This membrane is transparent, so it does not impair the bird's vision. Birds blink with their nictitating membrane about once per second, though this can vary.

Reptiles have a nictitating membrane that covers the entire eye. This membrane is transparent, so it does not impair the reptile's vision. While the exact rate can vary among species and individuals, reptiles typically blink with their nictitating membrane about once every few minutes.

Insects do not have eyelids. Instead, they have a layer of fluid that covers their eyes. This fluid helps to keep the eyes moist and clean. Insects do not blink in the same way that mammals or birds do, but they do have a way of moving their eyes to protect them from debris.