puncta

This is a small drainage hole located on the inner eyelid that drains excess tears into the nose. Normally, the tear film is generated from the inner eyelids and washes down the surface of the eye like a waterfall. The fluid then forms a small “lake” along the lower eyelid.  Tears from this lake drain through the punctum (the plural of puncta) and into a drainage canal under the skin. Eventually, the tears flow down the nasolacrimal duct and empty out into the nose. This pathway explains why people with runny eyes often have a runny nose as well. Some people have a problem with their puncta working correctly. Their puncta may be too small or may have been scarred shut from chronic lid irritation. Aging can cause the lower lid to loosen and rotate outwards so that the puncta is no longer able to reach the tear film at all. Some of these drainage problems can be fixed with surgery (but not easily). Puncta blockage is sometimes a good thing – with dry eye we occasionally block the puncta with temporary punctal plugs and we can even close the puncta permanently using cautery.