Blinking is a seemingly simple action but there are some rather complex reasons for this quick closing and opening of the eyes. But when we blink, what happens in the rest of the body and in the brain?
Over the centuries our bodies have developed certain protective and maintenance actions that we don’t have to think about. When we blink our world is completely blank for a split second. Yet the brain doesn’t register this, according to the best scientific research. Parts of the body that are involved in the blinking process include the cranial nerves, the Phrenic nerve, the trigeminal nerve, thoracic nerves and facial nerves.
In very basic terms, we blink to clean and lubricate the eyes. But beyond this “maintenance” activity, people also blink as a defensive reaction. Blinking helps keep the eyes moist and can help remove small particles and dust from the eyes. Some have compared our eyelids to the wipers we use on our car windshields. The difference is that we can blink consciously or the brain can have us blink when it is necessary, to put moisture on the eyes, not remove it as wipers do.
The eyes are moistened by several glands that produce an oily substance. When we blink, this substance helps keep the eyes lubricated. Of course, the eyelids can open and close quickly to help remove excess moisture too. However, lubrication is just one of the benefits of blinking.
Blinking also protects the eye from damage by objects from the outside. While the eyelashes work to keep dust and larger objects from the eye, the eyelids can block larger objects from contacting the eyeball. Both protection and lubrication take place several times each minute. Yet, most of the time we don’t even realize that we blinked.
Here’s how a great article in the Guardian (UK) explained it:
The brain has a reflex center in the upper cervical cord and in the brain stem. Estimates of how many times people blink range from once every four seconds to once every 10 seconds. What is fascinating is that the portion of the brain that controls our vision and processes what we see stops working for the split second that our eyes are closed. The Guardian reports that a university study shows we process information in a continuous manner and those “blink” moments don’t register.
The writer for the Guardian stated that this means we do miss things when we are blinking, at least in the sense that the brain doesn’t record any information for this time. But it also doesn’t recognize that we have been “in the dark” for that short time. The bottom line is that the body doesn’t usually let us suffer from these automatic actions. These actions develop to help us stay safe and healthy, while not allowing anything negative to happen.
The study indicated that if we put all the milliseconds together that we spend blinking this automatic action takes up about nine days each year. Of course, it’s so quick that our brain’s don’t’ even notice.