Tears are essential for our eyes to function properly. Your eye has special parts - called glands - that shed tears throughout the day. They usually produce only small tears - less than half a teaspoon a day. Tears are mainly water and a little salt, but they also contain oils, mucus, and chemicals called antibodies.
A small amount of oil in tears prevents them from evaporating or waking up in our eyes. If we do not have oil in our tears, it can make our eyes dry and really painful.
When you blink, the eyelid tears the eye and your mucus helps the tears to stick to the retina. Any tears that have left the discharge with a special water system that passes through your nose.
When we cry - and I hope you don't cry too often - we shed more tears than the eye. This is because the biggest tear gland can open up and produce many tears at once, just like a small fountain.