What are tears, afterall...

Today, while reading messages posted by friends and peace activists in response to the translation of a video song in Pashto on iPeace Network, it occured to me that there may be biological, physical, emotional and other countless explanations for tears, but they are telling on us in a language which is universal not only in human beings, but also among other living species on the earth.
The poetry of the video song is deeply moving as it touches on the emotional upheavels of millions of people displaced from their homes in their native region and their native country.
What are tears, afterall? In medical and literary terms it is a liquid produced by a process of crying, also called lacrimation.
Strong emtions, sorrow or joy, may lead to crying to produce tears in the eyes. So, we know that tears of any nature, whether of joy or sorrow, betray on our emtional and mental state, but at the same time they leave behind a refreshening effect, relieving pain and refining elation.
But, why do we cry and shed tears when sad or feeling sad for a loved one or over the sorrows of the fellow beings? It is human instinct, we cry to express our sorrows and joys. But, there are tears of gratitude. When we reminisce about good old happy days we are tearful. When we miss a friend or a loved one, we are tearful.
And, above all, I came to this... tears are the best universal expression of human emotions... and We can clean tears of those who cry of sorrow and turn the lacrimation to express joy and gratitude.
Let all thinking hearts and minds join efforts and pray together to end injustices from the face of earth and rekindle peace, hope and joy in their sorrowful lives.
With unconditional peace, love and light