Arnold Gould, age 11, of Tucson, Ariz., for his question:

WHY DO WE BLINK ALL THE TIME?

The shine in your bright eyes is moisture, very special moisture blended to clean and protect the surface of the eyeballs. This soothing lotion is manufactured in the tear glands, one under the outer corner of each lid. When we blink, the eyelids squeeze a little of this lotion from the tear glands and wash it across the surface of the eyes.

The blinking eyelids work somewhat like windshield wipers. They wash mini fragments of dust across the eyes, and the used moisture drains out through ducts at the inside corners of the eyes. The teary moisture is a cleansing lotion that also contains protective proteins and soothing ingredients to fight infections.