Lacrimal probing and syringing are performed to open blocked tear ducts. The procedure is usually performed under local anaesthetic. A thin flexible probe is inserted down the tear duct to check for any blockages, it may also clear any material causing obstruction. Once probing is completed, the area is flushed out with saline to confirm that the duct is open. If the tear duct remains blocked or if the tear ducts become blocked again, a thin tube may be inserted through the tear ducts to keep the drainage tract open. The tubes are made from silicone and are barely visible to the naked eye. They are normally left in place for several months and removed during a follow-up appointment.