Tears come mainly from the lacrimal glands located above each eyeball. These glands continuously produce tears that travel down ducts in the eyelids to the surface of the eyes, where blinking spreads them evenly to keep the eyes healthy and lubricated. Tears then drain out through small openings in the inner corners of the eyelids called puncta, leading into tear ducts and eventually the nose, where they evaporate or are reabsorbed.

There are three different types of tears, each from the lacrimal glands and other glands around the eyes:

• Basal tears: constantly produced to keep the eye moist and nourished.
• Reflex tears: produced in response to irritants like smoke or onions to flush the eye.
• Emotional tears: produced during emotional states and contain different chemical compositions than basal or reflex tears.

Additional tear components come from meibomian glands (oil layer) and goblet cells (mucus layer) in the eyelids, completing the tear film that protects the eyes.

In sum, tears originate primarily from the lacrimal glands above the eyes, supplemented by oils and mucus from other glands on the eyelids, and serve multiple protective and emotional functions.