Sneezes are uncontrollable. Small particles, such as pollen or dust, float up to your nose, irritate your membrane, and set off a chain of events. When an irritant comes into touch with your nasal mucosa, it activates the trigeminal nerve, which sends a signal to the medulla, which is located in the lower portion of the brain.

As a result, your chest expands, your lungs fill with air, and you sneeze all over the place. You sneeze up to 5,000 droplets of mucus and air at rates of up to 100 miles per hour.

Your eyelids close as a result of that response, but why is one of science’s great mysteries. We believe it is an automatic reaction, similar to how your leg twitches when you are touched on the knee. What may be the source of the problem? You can close your eyelids to prevent germs from falling into your eyes when you sneeze. Perhaps your eyelids are closed as a result of a succession of muscles tightening as a result of the automatic response.