Punctal plugs can relieve dry eye symptoms when drops or ointments fail. Punctal plugs are placed in the opening of the tear ducts (called “puncta”) in the eyelids to block tear drainage and keep the eyes moist. Implantation should reduce the need for artificial tear drops and increase the patient’s overall comfort.Punctal plugs come in a few different shapes and sizes, and may be placed in the lower or upper eyelid or both eyelids. The most common plugs are umbrella-shaped and made of silicone. They may be placed partially inside the tear duct or embedded entirely within the duct (Herrick plugs). A recently introduced acrylic plug called the SmartPLUG softens at body temperature and expands to custom-fit each patient’s eye.Implantation takes only a few seconds in a professional’s office. In some cases, before implantation, collagen is temporarily placed in the eye to predict the effectiveness of punctal plugs.