What is the chemical composition of tears?

An important component of tears is lysozyme, a chemical that inhibits bacterial growth on the eye's surface. Some of the tears evaporate, but the remainder is drained into the nose through the tear ducts, keeping the nose moist. Lysozyme from the tears prevents bacterial growth in the nose as well.

There are two types of tears:

1: Emotional ones (crying when emotionally upset and stressed) and

2: Ones arising from irritants (such as crying from onions).

It has been found that emotional tears contain more protein-based hormones, such as prolactin, adrenocorticotropic hormones, and leucine enkephalin (a natural painkiller), all of which are produced by our body when under stress. It seems that the body gets rid of these chemicals through tears. That explains why we usually feel better after a good cry.