Canalization of lacrimal vias

Tears are constantly being produced to help protect the surface of the eye, which drains into a small opening (tear spot) in the corner of the eye, near the nose. This opening is the entrance to the nasolacrimal duct; If this duct is blocked, tears will accumulate and spill down your cheeks (this happens even when you are not crying). In children, this duct may not be fully developed at birth (it may be closed or covered by a thin film, which causes a partial blockage) or in adults, the duct may be damaged by an infection, injury or a tumor.