Every minute, a person generates about 1 or 2 microliters worth of tears. They are a mix of oil, mucus, and water, secreted from different glands and cells around the eye. Tears serve to keep the eyeball surface lubricated. When you blink, your lids work like windshield wipers to push those tears into a pair of tiny holes called puncta, which lead to two sacs between the eyes. Blinking also squeezes those sacs, draining the liquid down the back of the nose and throat. This system operates throughout the day, though you’d never notice.