When we cry we put pressure into our heads. This pressure causes a backup of tears into our eyes from our noses. We also increase our blood flow to our face and eyes, which causes an increase in the amount of tears. These two things cause our eyes to be over filled with tears. And because we have too many tears to fit into our eyes, they flow down our cheeks .
Crying is innate, we produce 10 ounces per day and 30 gallons a year. When it comes to gender, it seems more women compared to men are shedding tears. Researchers believe this is because women are biologically wired to shed more tears than men, since female tear glands are much smaller than men’s.
The lacrimal gland, located in the outer part of the upper eye, is constantly secreting a protein-rich, antibacterial liquid. This fluid goes from the outer edge of the eyeball toward the cornea and lubricates the entire eye surface every time we blink.
The crying we are all familiar with is when excess liquid overwhelms the drains of the nasal canal of the tear duct, which overflows and falls down our cheeks. Basal tears are always in our eyes to serve the purpose of lubricating, nourishing, and protecting the eyes. The second type of tears, known as reflex tears, protect the eyes from irritants, including wind, smoke, or onions. The third type are those that are produced by emotion. Although these tears contain higher levels of stress, an endorphin and natural pain killer — they can also work by directly calming the iris down while signaling the emotional state to others.