The tears normally move towards the nose where they drain into the tear duct system through an opening (lacrimal punctum). The tears eventually drain into the nose through the naso-lacrimal duct. In infants, there may be a partial or complete blockage of the tear duct system, which can be seen by continual overflow of tears from the eye. Gradually this condition changes on its own or with massage of the lacrimal duct. In adults, the tear duct system may become obstructed from nasal infection or severe conjunctivitis.
Obstruction of the tear duct is caused by :
Inherited abnormality.
Bacterial infection of the duct.
Sinus or nasal infection, especially the long standing infections.
Eye infection.
Fracture of the nose or bones of the face.