Blockage or narrowing of the tube that normally drains tears from a child’s eyes. Many babies are born with the condition, usually because the membrane covering the ducts at birth fails to disappear. In older babies and children, blocked tear ducts most often result from an inflammation such as conjunctivitis. In newborns who have blocked tear ducts, tears flow heavily from the eyes rather than draining normally through ducts into the nose and throat. There may also be some discharge of mucus or pus. When tear duct obstruction is caused by infection, there may be redness, pain, and swelling in the eyes, in addition to excessive tears.