The science behind tears says that it's clear liquid secreted by the lacrimal glands(tear glands) found in the eyes of all the land mammals except goat and rabbit. Functions of tears 1.lubricating the eyes 2.removing irritants 3.and aiding the immune system Now comes the most common function..tears occur as a part of body's natural pain response. Pain response which means tears disclose the grief through eyes. Tears are a means of emotional response like grief or joy and it helps to release the stress. Just like other hormones release to build up the human body and helps to perform different functions of the body ..tears also helps to release the emotions and mental stress When in pain, we cry and tears roll down ..it shows how painful the reason is, which makes us cry. The reasons can be regret, inferiority, betrayal, chided by someone, beaten by someone, wound, anger, fear or anything which hurts. Sometimes we cry to express joy. sometimes tears trickle down due to humour...