Definition of Blocked tear duct:

A blocked tear duct is a partial or complete blockage in the system that carries tears away from the surface of the eye into the nose.

Causes, incidence, and risk factors:

A tube called the nasolacrimal duct normally drains tears from the surface of the eye into the nose. If this duct is blocked, the tears will build up and overflow onto the cheek, even when a person isn't crying.

In children, the duct may not be completely developed at birth. In adults, the duct can be damaged by infection, injury, or a tumor.