Even when you’re not cutting onions or watching Titanic, your eyes are constantly producing tears.
We actually produce three different types of tears: basal, reflex, and emotional. Basal tears and reflex tears are pretty easy to understand: they protect our eyes from debris or wash away potentially harmful substances and microorganisms.
However, scientists are only just beginning to deduce why we produce emotional tears – is it to release hormones, or more of a social signal?
Tearing, lacrimation, or lachrymation, (from Latin lacrima, meaning “tear”) is the secretion of tears, which often serves to clean and lubricate the eyes in response to an irritation of the eyes. They are formed through crying are associated with strong internal emotions, such as sorrow, elation, emotion, awe or pleasure. Laughing or yawning may also lead to their production.
This video by TED-Ed gives you the science behind sobbing with an animation of Iris, the iris.