Blocked tear ducts cause excessive tearing and eye irritation because the tears cannot drain normally. Typically, the tears drain out of small holes in the corner of the eye, and then pass through tiny tubes into the nose to be eliminated. Blocked tear ducts in adults may be caused by thickening of the tear duct lining, injury to the bones that hold and protect the eyes, a severe sinus infection, an abnormal growth of tissue in the nose or tumors, excessive growth of nasal bones, tumors or other abnormal tissue growths that block tear drainage, infection or inflammation that causes swelling and redness of the eyelid and surrounding skin, etc. Blocked tear duct may cause eye infections, blurry vision, pain and bloody tears. So if you suffer from tear blocked duct,can use warm compresses and take antibiotics to relieve the infections. Many doctors recommend waiting up to six months before considering treatment while they monitor the situation to prevent complications.