the them of the story shows emotions and intellect that can be cleary seen in every human being;however,we should learn to combine them ,in other words we should use them in a normal way.
Tears are made in the lacrimal glands and are a mixture of oils and water. If you don't have tears it can cause issues with your eyes becoming too dry. here is a wikipedia site about dry eye syndrome...
I got this from dictionary.com-
a drop of the saline, watery fluid continually secreted by the lacrimal glands between the surface of the eye and the eyelid, serving to moisten and lubricate these...