Crying by Tom Lutz From a physiological perspective, basal tears are the most common. They smooth out the irregularities of the cornea, allowing for vision as we know it. Reflex tears stream after a poke in the eye or the whiff of an onion.
Psychic tears accompany emotional trauma.
Of the three, psychic tears intrigue Lutz the most. He notes that humans have always cried, indeed, they cry from birth. In fact, babies cry an average of 4,000 times before reaching age 2. Fear, joy, and especially sadness trigger tears, but Lutz also shows how crying for these reasons differs between men and women, adults and children, and even various cultures. Emotional tears have concentrations of certain hormones different from those in reflex tears.