Puncta are the drainage ducts that your old tears, or extra tears, can escape through while your glands are making new ones. In each of your eyes, there is one punctum in the top eyelid and another on the bottom eyelid, at the corner of the eye that is towards your nose.

About 80% of the tears drain from the lower, 20% from the upper puncta. Fancy that — gravity applies, even in your eyes!

Punctal plugs do exactly what they sound like: They stop the drains, just like the plug in your kitchen sink. They are not quite as easy to put in as the plug in your sink, and they are definitely not as easy to get out. But, once in, they work just about as well.