How do your eyes keep clean and moist?

Your eyes stay clean and moist primarily due to tears, which are produced by the lacrimal glands. These tears provide lubrication, wash away debris, and contain antimicrobial proteins that help protect against infection. Additionally, the eyelids play a crucial role by spreading tears across the surface of the eye with each blink, ensuring even moisture and cleanliness. The conjunctiva, a membrane covering the eye, also helps keep the surface moist and protected.