There are times when eyes water, like when one feels overwhelmed by emotion, when one sneezes or has allergies, or when one is peeling onions. Tear experts mostly separate the droplets into three types. Basal tears are the tears that clean and lubricate the eyes, supporting vision. Reflex tears are the ones that flow out when eyes are irritated by something like the compounds in onions, pollen, bacteria. And emotional tears are well you know what they are for.
It starts with the lachrymal glands, situated on the outer portion of the upper eyes. These glands create and secrete tears. Most tears flow over the surface of the eyes and flow out through the corners of the eyelids, from the tear ducts, which lead to the nasal cavity. If you cry a lot, then the tears overflow the nasal cavity and start running out of your nose.
Even when one isn’t crying, tears flow from the lachrymal glands with every blink, moistening the eyes. This moisture is made up of water, oil, and mucus which help to maintain healthy vision in the eyes. Tears clear your eyes of dirt and allows light to enter the eyes so that one can see clearly.
Humans may have evolved tears that do more than only just eye-moistening as a means of survival. Evolutionary biologist Oren Hassan has suggested that we use tears to protect us from predators by making it harder to tell where we were gazing. Or, Hassan thought, maybe we evolved emotional tears as a way to show others that we were native and vulnerable, that we would prefer to be peaceful? When one sees a crying face, one feels an urge to ask what is wrong, to offer help or empathy. Probably it could be that emotional tears prove our willingness to trust and bond into supportive, protective communities.
Crying releases pent-up feelings and tension. But how we feel post crying depends on the circumstances and context of the crying. In a study including 5,000 men and women, many “good” and “bad” cry patterns emerged. Criers who were supported from those around them were much more likely to feel better after crying.