Sneezing is a natural protective reflex that occurs when the lining of the nose becomes irritated. It helps remove dust particles, various irritants and other tiny particles from the nasal cavity.

Before a sneeze occurs, sensory nerve endings in the nasal lining detect irritants and send signals to the brain. The brain then coordinates the movements of the respiratory muscles, chest and muscles around the throat. As a result, air is expelled forcefully through the nose and, in some cases, through the mouth.

Tiny droplets can also spread through the air during sneezing. For this reason, it is recommended to cover your nose and mouth with a disposable tissue or, if one is unavailable, sneeze into the inside of your elbow. Disposing of used tissues and washing your hands also help reduce the risk of spreading infectious diseases.

Why do we sneeze when exposed to bright light?

Some people sneeze repeatedly when they move from a dark place into bright sunlight or look towards a strong light source. This phenomenon is known as the photic sneeze reflex. It does not occur in everyone and is most often associated with an inherited trait.

The effect of bright light on the nervous system through the visual system may trigger the sneezing reflex. However, the exact mechanism behind this phenomenon has not yet been fully understood.

Some sources suggest that the photic sneeze reflex occurs in approximately 15–25 percent of people. However, this figure may vary depending on the research methods used and the groups of people studied.

Sneezing is generally a normal protective response of the body. However, if it occurs frequently and is accompanied by a runny nose, itching or watery eyes, the cause may be an allergy or other irritants.