The lacrimal drainage system consists of the puncta - upper and lower within the eyelids and which are the opening to the upper and lower canaliculus. These meet at the common canaliculus and open into the lacrimal (tear) sac. This runs parallel to the nose and is separated from the middle meatus of the nasal cavity by two thin plates of bone. It continues down to become the nasolacrimal duct (tear duct) which opens out into the inferior nasal meatus.
This is a companion discussion topic for the original article at https://patient.info/doctor/infectious-disease/dacryocystitis-and-canaliculitis