Blocked tear ducts are sometimes cleared using a procedure called intubation. During intubation, two small wire probes attached to silicone tubes are passed into the upper and lower tear duct openings (puncta) and down the tear duct drainage system into the nasal cavity. The wires are removed and the tubes are tied or sewn in place to keep the tear ducts open. Intubation is usually done as part of a probing procedure in the hospital using general anesthesia. Most people go home the same day.
From 3 to 16 weeks after surgery, the person returns to the doctor's office, and the tubes are removed. Anesthesia is usually not needed when the tubes are taken out.
The iris is a circular, pigmented membrane that provides the eye its color and the opening in the center is the pupil of the eye.
The iris is made up of muscular fibers that control the amount of light entering the pupil so that you can see clearly. The iris accomplishes this task by making the pupil smaller in bright light and larger in dim light.
In some people, the iris can become inflamed. This is termed iritis.