Basal tears are the continuous, thin layer of fluid that keeps the surface of the eye moist and comfortable. They are produced by the lacrimal glands and help to protect the cornea from dryness and irritation. Basal tears contain water, oils, and proteins, which work together to maintain eye health. These tears are different from reflex tears, which are produced in response to irritants like smoke or onions. Basal tears also play a role in providing nutrients to the eye and removing small particles, ensuring clear vision and overall eye function.