Drainage system for tears
The tear drainage system has two parts. The first part consists of two different types of glands that produce tears. These tear glands are found:
- In the lining of the eyelids. These glands (accessory lacrimal glands) start making tears at birth and constantly produce small amounts of tears that wash the surface of the eyes and prevent drying.
- In the bones that hold and protect the eyes (the orbits). These glands (main lacrimal glands) produce larger amounts of tears when a person cries or when something irritates the eyes, such as smoke. Usually, main lacrimal glands start making tears at birth but may not produce tears until several weeks later.
The second part of the system drains tears from the eyes into the nose.
- When your eye blinks, the lids push the tears across the eye into the drains (puncta) at the inner corner.
- The drains empty into channels (canaliculi) that connect the eye with the nose. The channels drain into tear sacs (lacrimal sacs) that lie beside the nose.
- The sacs narrow into tear ducts (lacrimal ducts) that drain through the nasal bone into the nostrils.
See an illustration of the tear duct drainage system
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| Author: | Debby Golonka, MPH | Last Updated: April 11, 2008 |
| Medical Review: | Kathleen Romito, MD - Family Medicine Christopher J. Rudnisky, MD, FRCSC - Ophthalmology | |
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