Punctal plugs

Punctal plugs (or punctual plugs) are small medical devices shaped somewhat like golf tees that are inserted into the tear ducts (puncta) of the eyes to block them. This prevents the drainage of liquid from the eyes. They are used to treat dry eye.

A temporary punctal occlusion can be inserted and tried first. These are made of collagen and are dissolvable. This is to ascertain that permanent ones will not cause excessive tearing.

Permanent punctal plugs are usually made of silicone. Some plugs are made of thermally reactive material. Some of these are inserted into the punctum as a liquid and then they harden and conform to the individual's drainage system. Others start out rigid and become soft and flexible, adapting to the individual's punctal size after they are inserted.

Artificial tears are usually still required after punctal plug insertion.

Risks
The risks of punctal plugs are fairly minimal. There is a risk of eye irritation, excessive tearing, and, in rare cases, infection.