You can think of tears like a shower or bath for your eyes. Special tear glands — called lacrimal glands — produce tears. Every time you blink, a tiny amount of tears is spread across your eyes by your upper eyelids.
These tears help to keep your eyes clean. They wash away dust, germs, and other types of tiny particles that you don’t want in your eyes. They also keep your eyes moist. If you’ve ever had dry eyes, you know how painful and sore they can get if they don’t have the right amount of moisture.
If tears wash your eyes every time you blink, why don’t we always look like we’re crying? After the tears wash and moisturize our eyes, they drain through special tear ducts — called lacrimal ducts — in the corners of our eyes. Your tear ducts are like tiny bathtub drains that funnel tears from your eyes to the back of your nose and down your throat.
Sometimes, though, our eyes produce more tears than our tear ducts can drain. When this happens, the tears spill over our lower eyelids and down our faces. That’s what we call crying.
Crying can be triggered by both mental and physical causes. Physical causes might include irritants, such as smoke or allergens, or gases, such as the gases onions release when they’re sliced open. Anything that irritates your eyes can cause tears.
Mental causes can encompass just about any type of strong emotion, from sadness to happiness. In these situations, your brain senses these emotions and tells your lacrimal glands to produce lots of tears.
But why would your brain tell your lacrimal glands to produce tears in response to strong emotions? Scientists have a few theories. Some believe that crying helps to release toxins and stress hormones from the body.
Others believe tears perform a social function by drawing others to help you in a time of stress or great need. Whatever the reason might be, tears are beneficial to our eyes and help keep us healthy. So don’t be afraid to cry. Your eyes can always use a good bath!