What is the primary role of basal tears?

The primary role of basal tears is to provide a moisture film for the eye. Basal tears are continuously produced by the lacrimal glands and serve to maintain the health of the corneal surface. This moisture is essential for providing a stable environment for the eye, preventing dryness and allowing for smooth movement of the eyelids over the eye.

In addition to keeping the eye moist, basal tears also contain nutrients and proteins that contribute to the overall health of the eye. They form the first layer of the tear film, which protects the ocular surface and helps to maintain clarity of vision.

While other types of tears, such as reflex tears, help wash away irritants and foreign particles, and emotional tears are triggered by feelings, basal tears play a fundamental role in the everyday function and protection of the eyes, which is why the correct answer highlights their role in providing a moisture film.