Definition of Blocked tear duct:

A blocked treat duct describes a partial or complete blockage in the tear duct system. This duct system carries tears away from the surface of the eye, into the nose.

Causes, incidence, and risk factors:

Tears from the surface of the eye are normally drained into the nose by a convoluted tube called the nasolacrimal duct. If this duct is blocked, the tears will accumulate and overflow onto the cheek, even when a person isn't crying.

In children, the duct may not be completely developed at birth. This problem often disappears on its own. In adults, the duct can be damaged by infection, injury or tumor.