The lacrimal punctum (plural ''puncta'') or lacrimal point, is a minute opening on the summits of the
lacrimal papillae, seen on the margins of the
eyelid
An eyelid is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. The human eye ...
s at the lateral extremity of the
lacrimal lake. There are two lacrimal puncta in the medial (inside) portion of each eyelid. Normally, the puncta dip into the lacrimal lake.
Together, they function to collect tears produced by the
lacrimal gland
The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each or ...
s. The fluid is conveyed through the
lacrimal canaliculi to the
lacrimal sac
The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla. It connects the lacrimal canaliculi, which drain tears from the ...
, and thence via the
nasolacrimal duct
The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. T ...
to the
inferior nasal meatus of the
nasal passage.
Additional images
File:Lacrimal punctum.jpg, A close up of a lacrimal punctum.
File:Lower lacrimal punctum.jpg, Lower lacrimal punctum through slit lamp biomicroscope
See also
*
Imperforate lacrimal punctum
*
Lacrimal apparatus
*
Punctal plug
References
External links
Diagram and discussion at aafp.org
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Human eye anatomy