[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Ophthalmology](https://durgical.com/en/ophthalmology/) › [Clinical anatomy and physiology](https://durgical.com/en/ophthalmology/areas/anatomy-physiology/) › Tear production and drainage # Tear production and drainage - Anatomy and physiology Tears are made in the upper outer orbit and drain through two small openings at the inner corner into the nose. A block anywhere makes the eye water. Updated Nov 5, 2026 **See it in 3D:** [Lacrimal gland](https://durgical.com/en/anatomy/lacrimal-gland/) · [Tear drainage](https://durgical.com/en/anatomy/lacrimal-canaliculus/) · [Lacrimal bones](https://durgical.com/en/anatomy/lacrimal-bone/) · [Orbicularis oculi](https://durgical.com/en/anatomy/orbital-part-of-orbicularis-oculi/) ## Key points - Gland upper outer orbit; drainage through the puncta at the inner corner. - Duct opens under the inferior turbinate (valve of Hasner). - Secretion: parasympathetic, facial nerve. - Dacryocystitis: swelling below the medial canthal tendon. ## What it is The main lacrimal gland lies in the upper outer part of the orbit and produces reflex tears; small accessory glands in the conjunctiva produce the basal flow. Tears cross the eye with each blink and enter the puncta, two small openings on the inner lid margins. They pass through the canaliculi to the lacrimal sac and down the nasolacrimal duct into the nose, under the inferior turbinate. ## Clinical anatomy - Lacrimal gland: orbital and palpebral lobes, in a fossa of the frontal bone. - Puncta and canaliculi in the upper and lower lids, joining into a common canaliculus. - Lacrimal sac in a bony fossa at the inner corner of the orbit, below the medial canthal tendon. - Nasolacrimal duct opening into the inferior meatus of the nose, guarded by a mucosal valve (valve of Hasner). ## Physiology - Parasympathetic fibres from the facial nerve (via the greater petrosal nerve and the pterygopalatine ganglion) drive tear secretion. - Blinking works as a pump: the orbicularis muscle squeezes tears through the canaliculi into the sac. - Tears drain into the nose, which is why crying causes a runny nose. ## Clinical correlation - Congenital nasolacrimal duct obstruction is a membrane at the valve of Hasner that has not opened; most open in the first year. - Acute dacryocystitis is an infected, obstructed sac: a tender swelling below the medial canthal tendon. - A facial nerve lesion near the geniculate ganglion reduces tearing; a lax lower lid or weak orbicularis impairs drainage. - Lacerations at the inner lid can cut the canaliculi. ## Next step / Initial management - Infant with a watery, sticky, white eye: sac massage and observation; probing if it persists beyond about a year. - Adult with a watery eye and mucus on pressing the sac: ophthalmology for syringing and possible dacryocystorhinostomy. - Acute dacryocystitis: antibiotics and ophthalmology. - Inner lid laceration: ophthalmology for canalicular repair. ## Test yourself Think of the answer, then tap the question to see it. ## Where does the nasolacrimal duct open? Into the inferior meatus of the nose, under the inferior turbinate. ## Which nerve carries the secretory fibres to the lacrimal gland? The facial nerve, through the greater petrosal nerve and the pterygopalatine ganglion. ## What causes congenital nasolacrimal duct obstruction? A membrane at the lower end of the duct (valve of Hasner) that has not opened at birth. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/ophthalmology/tear-production-and-drainage/) ## Elsewhere in DurgiPedia - [Conjunctiva, eyelid glands and lacrimal gland](https://durgical.com/en/histology/conjunctiva-eyelid-glands-and-lacrimal-gland/) ## Connections ## See it in 3D 4 The structures of Durgical's 3D anatomy where it is found. - [Lacrimal gland](https://durgical.com/en/anatomy/lacrimal-gland/) - [Tear drainage](https://durgical.com/en/anatomy/lacrimal-canaliculus/) - [Lacrimal bones](https://durgical.com/en/anatomy/lacrimal-bone/) - [Orbicularis oculi](https://durgical.com/en/anatomy/orbital-part-of-orbicularis-oculi/) ## Related 3 - [The watering eye (epiphora)](https://durgical.com/en/ophthalmology/the-watering-eye/) - [The tear film and ocular surface](https://durgical.com/en/ophthalmology/the-tear-film-and-ocular-surface/) - [Eyelid lacerations: which to refer](https://durgical.com/en/ophthalmology/eyelid-lacerations-which-to-refer/) ## Related conditions 3 - [Dacryocystitis and nasolacrimal duct obstruction](https://durgical.com/en/conditions/dacryocystitis-and-nasolacrimal-duct-obstruction/) - [Dry eye disease](https://durgical.com/en/conditions/dry-eye-disease/) - [Bell palsy](https://durgical.com/en/conditions/bell-palsy/) [← All of ophthalmology](https://durgical.com/en/ophthalmology/) Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once. Sources: [Anatomy, Head and Neck: Eye Lacrimal Gland](https://www.ncbi.nlm.nih.gov/books/NBK532914/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Anatomy, Head and Neck: Eye Lacrimal Duct](https://www.ncbi.nlm.nih.gov/books/NBK531487/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Congenital Nasolacrimal Duct Obstruction](https://www.ncbi.nlm.nih.gov/books/NBK559267/) (StatPearls Publishing (NCBI Bookshelf), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/ophthalmology/tear-production-and-drainage/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/ophthalmology/tear-production-and-drainage/