Blinking is something humans (and virtually all other creatures) do involuntarily, just like breathing or swallowing. Obviously excluding animals like fish and snakes, which do not have eyelids, everybody and every animal blinks at varying rates. Eyelids are designed to keep the eyes safe, moist, and free of debris, and blinking is a mechanism intended to make sure that the eyelids are constantly doing their job. Thanks to science, it is now widely known that the average person blinks 15-20 times per minute, and nearly 29,000 times per day.
Why Do We Blink So Much?
The rate of blinking often depends on the activity, and is often a way for scientists to study how much brain activity is consumed by a specific action. Blinking is also a way for individuals to focus, as we blink much less when we are looking intensely at a screen, printed material, or even lying. According to a study published in the journal Frontiers in Psychology, people who lie intentionally blink less. This phenomenon is believed to be related to the fact that lying consumes more attention than telling the truth.
According to a paper in Proceedings of the National Academy of Sciences, people watching movies blink less, and enter a state of increased brain activity. However, when they do blink, their brain function spikes in areas related to rest, and the focus centers in the brain are better able to stay activated for a few seconds when the person opened his or her eyes.
To support this theory, the researchers also turned off the film for fractions of a second, just like the span of a blink, to see if the same response was given; the brain did not react like it did when a person physically blinked. It is believed that the brain looks for natural pauses in activity, as it means less likelihood that something will be missed.
The scientists working on this experiment believe that blinking can be connected to increasing attention or focus on something, as it “wipes the slate clean” enough, or provides enough of a respite from input. This indicates that the slower the blinking, the more engaged the brain is.
Researchers have explained that slowed blinking, in evolutionary terms, was a way to allow our ancestors the ability to focus on their prey (or their predators) without needing to clear their sight. The person who blinked too much would miss their prey running, or even worse, miss a predator attacking. If humans blinked too much, they would have died out thousands of years ago!
Talking, Gender, and Age
According to the Institute of Neurology in Rome, other experiments have found that people blink as much as 577 percent more when they’re talking or stressed. This indicates that the brain is “overloaded” and attempting to focus. Strangely enough, women often blink faster than men, especially women on the pill, even though science cannot explain this.
According to Annual Neurology, women are believed to blink, on average, twice as much as men and up to 32 percent more if they’re on birth control. This number increases dramatically if a woman is excited or stressed, and many researchers believe it indicates a woman’s different connections and activity in the brain based on cortisol and other stimulants. Women also talk faster than men, and talk more than men. It appears that, in general, women do more than men in every arena of life.
Infants only blink a couple of times in the span of a minute, which further supports the idea that blinking is related to brain function (something an infant has yet to develop). It is believed that children and young teens still only blink about half as much as their adult counterparts until they reach 15 years of age.
While they are officially unexplained, many theories about children’s blink rates indicate that it could be how much sleep they receive (12-18 hours depending on age). By that logic, adults blink much more often to clear their eyes of the tears they shed because they haven’t slept since their children were born!
Other researchers believe it is because children focus so much in their early years in order to acquire more information. As in the movie-watching study, focusing leads to less blinking.
Why Do Our Eyes Blink at the Same Time?
Very rarely do animals blink one eye at a time involuntarily (turtles and hamsters often do this), and humans only blink one eye intentionally. When we attempt to blink just one eye, or more likely just attempt to wink, it takes a lot more work than just blinking. It takes extra facial muscles to hold one eye open while the other one closes, and it takes mental focus that blinking does not require. That’s why you look so ridiculous when winking.
There are many reasons why we, as humans do not blink one eye at a time. For example, when you try to blink one eye (or just close one eye at a time), the focus of your sight moves drastically. Just try it. If you close your left eye, the object appears further to the right, and vice versa.
Evolutionarily speaking, this would not have been helpful because we wouldn’t have been able to hunt effectively, run, or survive in general. It also takes much longer for eyes to focus when they blink one at a time, which means that blinking individually would take away from the attention needed to survive in the “Caveman Days.” It also would have scared all of the cavewomen away, because winking probably looked a lot more ridiculous back then.
Also, our brains work symmetrically. Have you ever tried patting your head and rubbing your belly at the same time? It just doesn’t work; you end up either patting or rubbing both areas. Blinking one eye at a time has a similar effect, by throwing off the symmetry your brain is used to. This also explains why it’s so hard to blink one eye at a time – our brains are not wired to allow that behavior to occur, so it takes excessive focus.
Why Does it Matter?
In reality, we blink much more than is necessary to maintain eye lubrication and cleanliness. This leads many researchers and scientists to explore the causes, benefits, and differences in blinking styles. Scientific breakthroughs have shown that many people differ in their blinking rates, but not because of any characteristics that would be expected.
Instead, we’re finding that blinking differs across genders, can be affected by medical differences (the pill, Tourette’s, and Parkinson’s), and increases or decreases based on our stimulus levels. Because of these fascinating findings, the “habit” of blinking is much more important than originally thought, and can be used in a number of applications, such as health and mental screenings, judicial processes, and brain studies.
Odds are you blinked a lot less while reading this article, so take a break, blink a few times, and give your eyes a rest, they deserve it.