Why do you reflexively close your eyes when you hear a big noise?

People and animals close eyes and hear large sounds, they close their eyes quickly. This is not consciously done, it is an action taken unconsciously, and John Furnace who is a professor of neuroscience at Melbourne University explains this reflexive behavior.

Curious Kids: Why do you blink when there is a sudden loud noise close by?
https://theconversation.com/curious-kids-why-do-you-blink-when-there-is-a-sudden-loud-noise-close-by-99437

Suddenly listening to loud noise, reflexively blinking eyes are called blink reflex, and it is executed in about 0.01 second after checking things with eyes and ears. Since blink reflex reacts and acts before the brain recognizes it, it does not consciously and acts to close the eyes unconsciously.

Eyes play a very important role also to get information, delicate items that can not be easily repaired by injury. For this reason, when people and animals get loud noise in the vicinity, it seems like they take actions to protect their eyes from the danger that they may fly something towards important eyes in order to live It is thought that it became. Eyeblink reflection occurs not only in the case of a loud sound, but also when it suddenly receives strong light in the eyes or when something jumps into the eyes, to protect the eyes.

The mechanism by which blink reflex is performed is characterized by a distinctly short number of steps until action occurs, unlike "Behavior that actually closes eyes after confirming something with eyes and ears". Normally, this information is transmitted to the cerebral cortex through the brainstem when we obtain information that "dangers are approaching to the eyes". Then, after the information is processed in the brain, the command to "close the eyes" is transmitted to the eyes via the brainstem and actions are taken to close the eyes. In this way consciously doing things requires a number of steps, the more steps, the more it will take time, so it will be difficult to respond instantaneously.

Therefore, in the blink reflex, skipping the step of processing in this brain, as soon as the brainstem receives information, we will send a command to "eye catch". In other words, because it is possible to close your eyes with only 3 steps of "obtain information from the eyes", "confirm the information with the brainstem" and "execute", so that you can take action to protect your eyes in a short time of about 0.01 seconds That is why.

Besides blink reflex, there are many reflexive behaviors performed unconsciously. When you touch a hot thing, you can withdraw your hand immediately, suddenly pressed by someone when you stumble on it, stomp on it, even at various parts of the body We will do a kind of action. Also, suddenly something comes to the eyes, not only closing the eyes, but also actions to avoid or cover the eyes with hands, people and animals using various reflexive behaviors from danger I am protecting you.