Kurt Jensen, age 10, Omaha, Nebr.,, for his question:

Tears are not only for crying. The moisture from which they are made has a far more important job to do, a job which keeps it busy all day and every day. It has to keep your eyes washed and shiny bright. Every time you blink a little tear juice is washed over your eyes. For your bright eyes must always be slightly moist.

Tear juice is made in glands about the size and shape of almond nuts. There are two of these little factories, one under each upper eyelid near the outside corner, ill day long, these busy tear glands are making tear juice from avatar and salt in the body.

We blink our eyes about once every six seconds. With every blink, a little tear juice is washed over the surface of the eyes. Small bits of dust are wiped away and the eyes get the; moisture they need.

This tear juice is squeezed out of the tear glands by muscles in the upper eyelid. Try blinking your eyes fast for a few moments. Pretty soon your eyes will be swimming in tear juice. The face muscles have been squeezing the tear glands and forcing them to do extra work, make extra tear juice.

When we cry or laugh a lot, we tend to make faces. This pulls the muscles all out of shape. The busy tear lands get overworked. They make extra tear juice and there is an overflow. We can spill just as many tears from laughing as we can from crying.

Most of the: time, however, we are not laughing or crying. The tear glands make just enough juice for the ‑eyelids to blink. The eyelids work like windshield wipers, spreading a little moisture; every time they move down over the eyes.

Not much tear juice is needed for this job. But even so there must be a place to put the waste tear juice that collects during the day. To take care of this, each eye has a tiny garbage disposal unit. This is a little outlet called a tour duct. It is a tiny tunnel that runs from the lower eyelid into the nose. Get a mirror and gently roll down the lower inside corner of one of your eyes. The little hole you see there is the tear duct. It leads into the back of your nose, Down this tunnel goes the waste tear juice which the eyelids have already used to polish up your eyes.

The tear duct is only large enough to carry the everyday moisture from the eyes. When we cry or laugh a lot, extra juice floods into the eyes. The tear duct carries away as much as it can. The back of the nose gets flooded and we feel sniffly. Still more: tears flow with no place to go. They fill up the eyes and then start running in rivers down the cheeks,