[1] The upper lacrimal drainage system starts at the puncta, canaliculi, and the common internal puncta (opening of common canaliculus) and drains into the lacrimal sac. The lower lacrimal ...

Medically reviewed by Andrew Greenberg, MD Punctal plugs are devices used to treat dry eyes that are placed inside the tear ducts. They help keep eyes moist by preventing fluid, such as tears, from ...