Useless fact
What is the tiny hole in your eyelid called?
The tiny hole in the inner corner of each eyelid that drains tears is called the lacrimal punctum.
The lacrimal punctum is a minute opening located on the margins of the eyelids, specifically at the inner corner near the nose. Humans typically have four puncta in total, one on each of the upper and lower eyelids. These tiny holes serve as the entrance to the lacrimal drainage system. When you blink, your eyelids push tears across the surface of the eye toward these openings. From the puncta, tears flow into the lacrimal canaliculi, then into the lacrimal sac, and eventually drain into the nasal cavity, which is why your nose runs when you cry. The anatomical structure of this system has been studied and documented since ancient Greece, but detailed descriptions of the fluid mechanics were solidified during the Renaissance and later refined by modern ophthalmologists. In medical practice, if a patient suffers from dry eyes, doctors sometimes insert tiny silicone plugs, known as punctal plugs, into these openings to block the drainage of tears and keep the eyes moist.
Why this is true — The term 'lacrimal punctum' is the standard anatomical term for the minute openings on the eyelid margins that drain tears into the lacrimal system, as documented by major medical and ophthalmological associations.
Sources
- How the Tear Drainage System Works American Academy of Ophthalmology