Whenever somebody weeps, tears come out from eyes. Do you know why it happens?
We blink our eyes – like the stage curtains – by means of muscles. The movement of the eyelids is so fast that it does not disturb our vision. The blinking of the eyes is an involuntary action. This takes place every six seconds throughout our life.
In each eye, there is a ‘tear gland’ located at the outer corner of the eye. There are small tubes or ducts which carry the tears to the upper eyelids and from there they are taken out of the eyes by other ducts.
Every time we blink our eyes, some fluid comes out through the openings of the tear ducts. This keeps the eyes lubricated and prevents them from drying. When we weep, more fluid comes out through openings of the ducts in the form of tears. It is a reflex action that occurs without our control.
Sometimes tears come out even when we laugh a great deal. That is because, when we laugh, the muscles squeeze the tear glands, due to which tears begin to flow out.
When we cut onions, tears can come out of our eyes. In fact, the onion gives off an irritating volatile substance. When it reaches our eyes tears are produced to protect the eye from irritation. The tears ‘wash’ the irritating substance away. The same thing happens with smoke.
Some sad news also produces tears by reflex action. This happens only when we do not have words to express our feelings.