The lacrimal drainage system is situated in the anteromedial orbit. The upper and lower puncta are openings about 0.3 mm in diameter, 4.5 - 6 mm from the medial canthus in the medial upper and lower eyelids. Horizontal canaliculi are about 8 mm in length and carry tears from the puncta to the lacrimal sac. The lacrimal sac and duct transmit tears to the nose where they empty through the valve of Hasner beneath the inferior nasal turbinate.