Why Do Eyes Water?
You're walking home from school on a windy November day when — whoosh! — a breezy blast smacks you in the face. As your teeth start to chatter and you pull your jacket closed, you notice your eyes are tearing up. Your eyes are tearing, but you're not sad. What's going on? Your eyes are "watering."
Tell Me About Tears
When your eyes water, they're making tears, just like when you cry. The tears from watering help protect your eyes. How? By keeping them moist and washing out dust and other foreign stuff that gets in there. The tears from watering eyes might only fill your eyes or they might trickle down your face.
Whether you're crying or your eyes are just tearing, the liquid in your eyes is created the same way. All tears come out of tear glands, or lacrimal (say: LAH-krum-ul) glands, found way up under your upper eyelids. Tears wash down from the glands and over your eyes.
Some of the tears drain out of your eyes through tear ducts, or lacrimal ducts. These ducts are tiny tubes that run between your eyes and your nose. Each tear duct is like a tiny bathtub drain. When the tears fill up your eyes, they drain out through the tear ducts. You have two tear ducts — one near the inside corner of each eye. You can see these holes if you gently pull down your lower eyelid a bit.
If tears are flowing quickly, like when you're crying pretty hard, the ducts can't drain them all, so tears run down your face. And have you ever noticed that your nose sometimes runs when you cry? That's because some of the tears making their exit through the ducts end up coming out of your nose.
Why Do Eyes Water?
Eyes water for lots of different reasons besides crying. Anything that irritates the eye can bring on tears because the eye will try to wash it out. So when something gets stuck in there — like dirt or an eyelash — here come the tears!
You can't always see the stuff that gets in your eyes. Have you ever walked into a smoky room? If so, you may have noticed your eyes tearing up as protection against the smoke. Even though the particles that make up smoke are too small to see, they can still bug your eyes. Eyes might also water if you're around an onion that's being peeled or chopped. The fumes onions give off actually contain tiny chemicals that can get in your eyes and make them hurt.
Things that can dry out your eyes, like cold air or wind, will make eyes water, too. To protect the eyes from getting too dry, the tear glands crank out the tears. Imagine skiing down a hill with dry eyes as all that wind rushed at you. That would really hurt!
People's eyes also tear when they have allergies; infections like a cold; or pinkeye, known as conjunctivitis (say: con-JUNK-tih-vie-tis). All of these irritations can inflame the eyes and make them water.
Tear Trouble
You might not think twice about your watering eyes, but some people do have trouble making tears because their tear glands don't produce enough tears. Certain medical conditions or medicines can cause dry eyes.
Another problem is not being able to drain the tears, so the eyes can get too full of liquid. This may happen because someone has a blocked tear duct. Babies can be born with blocked lacrimal ducts. They usually open on their own, but some babies need a small operation to clear the ducts.
So now you know what your eyes are up to when they get all wet. It's such a beautiful story, it brought tears to our eyes!