Crying is the shedding of tears (or welling of tears in the eyes) in response to an emotional state, pain or a physical irritation of the eye. Emotions that can lead to crying include anger, happiness, or sadness. The act of crying has been defined as “a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus, without any irritation of the ocular structures”, instead, giving a relief which protects from conjunctivitis. A related medical term is lacrimation, which also refers to non-emotional shedding of tears. Various forms of crying are known as sobbing, weeping, wailing, whimpering, bawling, and blubbering.
So essentially, we cry in extreme emotional situations, whether that be anger, happiness or sadness. And extreme pain. Oh, and onions.
Take a moment and stare and something. Hold your eyes open long enough so that tears come out. So there is a limit to how long you can hold your eyes open without blinking, right? And typically, at that point, your eyes will water.
So if we take our view of time dilation as it relates to stress, the human perception of time contracts as the stress increases. So in your most emotional moments, your brain is so active, that seconds seem like minutes. Time literally freezes. And if time froze when your eyes were open, you know what would happen? Your eyes would dry out. So you produce tears. Crying is a symptom of high brain activity which drastically slows the individual’s perception of time.