Tears are important. Without tears, we’d have no eyeballs, at least not ones that functioned, anyhow.
For our eyes to see properly, they have to maintain a constant layer of moisture over the tops. So our tears are constantly bathing our eyes, to the tune of 10 ounces a day and 30 gallons a year. The reason we don’t notice almost an entire can of Coke’s worth of liquid soaking into our sockets daily is that our bodies are set up for seamless tear production and removal. The only time we notice them is when something goes wrong. (Side note: Do not — I repeat — do not ever Google “weirdest things stuck in eyes.” I think I have suffered enough for all of us.)
But not all tears are created equal, according to a recent TED-Ed video titled Why We Cry. The tears you cry over a Nicholas Sparks movie aren’t the same kind you cry when making spicy salsa. All tears start with three layers to keep eyes moist and protected: the mucous, aqueous and lipid layers. But what’s in those layers are different depending on the type of tears you’re crying. That’s right — your body is a magical factory of salty water that can produce three totally different types of cheek streakers.
Basal tears are the most common type. They’re the ones responsible for all the daily, constant upkeep and overall health of your oculars. Who knew your peepers were so high maintenance? But while they’re the hardest working, they’re also the least interesting.
Things start to get good with the second type, called reflex tears. As the name suggests, this type of tears are in reaction to an outside stimulus, like cutting an onion, smelling a noxious gas, bright sunlight or that time my toddler hit me right between the eyes with a metal Thomas the Tank engine. (I learned about involuntary tears, and he learned the F-word. It was a learning experience all around.) Reflex tears are released automatically and in large amounts to wash away toxins. The aqueous layer also contains antibodies to stop microorganisms and other germs from infecting your eyes.
The last type, and the ones we think about the most, are emotional tears. Whether you’re feeling too happy from watching all those videos of soldiers surprising their kids for Christmas or you’re feeling too sad because something horrible happened, your body turns on the full waterworks. They can range from the wedding-approved single tear balancing on your cheek to a full-on Oprah, ugly cry, complete with heaving sobs. But whatever form they take, scientists think they’re there to help stabilize that out-of-control feeling and help you calm down.
More: 18 Movies guaranteed to make you cry
It’s true: Crying really does help you feel better. On the outside, tears may help you by eliciting sympathy from others. But the emotional tears themselves help to get you through the rough patch, as they contain higher levels of stress hormones and enkephalin, a compound that works as a natural endorphin and painkiller.
So the next time you’re having a good sobfest and someone tells you to stop being such a baby, you can tell them to zip it, because tears are a necessary part of good emotional and physical health. (Not recommended, but perhaps easier if you’re crying hard: hitting them between the eyes with a Thomas the Tank engine.)