lacrimal sac

anatomy

Also known as: lachrymal sac

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 30, 2026

Quick Summary

The lacrimal sac is a crucial part of the eye's tear drainage system. Located at the inner corner of the eye, it acts as a reservoir where tears collect before being channeled into the nose via the nasolacrimal duct.123

Tears are produced by the lacrimal glands and spread across the eye's surface to keep it moist and clean. Excess tears then flow towards the nose through small openings called puncta, which lead into the canaliculi and then into the lacrimal sac.23

Inflammation of the lacrimal sac, known as dacryocystitis, is a common condition that can cause painful swelling at the inner corner of the eye. Blockages in the nasolacrimal duct can also lead to a watery eye and may require treatment, especially in infants.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

tear duct and glands
The canaliculi lead to the lacrimal sac near the inner corner of each eye, which itself empties into the nasolacrimal duct, a tubelike structure that directs tears into the nasal cavity.
Read More
The canaliculi lead to the lacrimal sac near the inner corner of each eye, which itself empties into the nasolacrimal duct, a tubelike structure that directs tears into the nasal cavity.
Read More