The science bit…
Tears contain an antibacterial enzyme (a protein) called lysozyme that clears the eyes during blinks. They are produced in lacrimal glands in the upper eyelids and are slightly alkaline and saline (i.e. salty).
Tears can be either emotional or reflex. Emotional tears are shed as a response to stress or a situation (sad or happy). Reflex tears just like yawning cannot be controlled (you experience this when your eyes get irritated e.g. by wind).
The social bit…
Women’s tears compared to men’s tears are not only caused by physical situations like pain (because women have a higher pain threshold than men, which is needed for childbirth). Hormonal imbalance or sensitivity causes tears to be produced in tear glands.
Even though most societies frown upon men crying (they learn to hold it in), it is natural for all humans to cry.
A little boy asked his mother, “Why are you crying?”
“Because I’m a woman,” she told him.
“I don’t understand,” he said.
His mum just hugged him and said,
“And you never will.”
Later the little boy asked his father, “Why does mother seem to cry for no reason?”
“All women cry for no reason,” was all his dad could say.
The little boy grew up and became a man, still wondering why women cry. Finally, he put in a call to the Sovereign Being. When He got on the phone, he asked, “Why do women cry so easily?”
“When I made the woman, she had to be special. I made her shoulders strong enough to carry the weight of the world, yet gentle enough to give comfort.
I gave her an inner strength to endure childbirth and the rejection that many times comes from her children.
I gave her a hardness that allows her to keep going when everyone else gives up, and take care of her family through sickness and fatigue without complaining.
I gave her the sensitivity to love her children under all circumstances, even when her child has hurt her very badly.
I gave her strength to carry her husband through his faults and fashioned her from his rib to protect his heart. I gave her wisdom to know that a good husband never hurts his wife, but sometimes tests her strengths and her resolve to stand beside him unfalteringly.
Finally, I gave her a tear to shed. This is hers exclusively to use whenever it is needed. “You see my son,” He said, “the beauty of a woman is not in the clothes she wears, the figure that she carries or the way she combs her hair. The beauty of a woman must be seen in her eyes, because that is the doorway to her heart – the place where love resides.”
– Author Unknown-