Causes of Tear Duct Blockage

Authored by Dr Colin Tidy, 12 May 2017

Patient is a certified member of
The Information Standard

Reviewed by:
Dr Adrian Bonsall, 12 May 2017

About 1 in 5 newborn babies will have a tear duct (nasolacrimal duct) that is not quite fully developed at birth.

The surface of the eye is kept moist by watery fluid (tears). This is really important to prevent any damage to the sensitive surface of the eye. The tears help to remove any dust or dirt from the surface of the eye. The tears are made in glands called the lacrimal glands, which are just above the outside corner of the eye, below the eyebrow.

Diagram showing eye and tear production

The lacrimal glands constantly make a small amount of tears which drains on to the eye.

When we blink, the eyelid spreads the tears all over the surface of the eye. Any excess tears drain out of the eye by passing through the small channels of the tear duct (nasolacrimal duct) and into the nose. There are also tiny glands (called meibomian glands) in the eyelids, which make a small amount of oily liquid. This oily liquid also helps to protect the surface of the eyes.

Blockage of the tear duct is quite common in babies and is usually because the tear duct has not completely developed by the time of the birth. The blockage of the tear duct can affect just one eye or both eyes.

Abnormalities of the eye or the eyelids can also cause a blockage of the tears in babies but this is very rare.

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