Excessive watering or tearing of the eyes (epiphora) can be a symptom of faulty tear drainage, poor eyelid tone or, less commonly, excess tear production. Tears are produced by glands within and around the eyelids. They then evaporate from the surface of the eye and drain through ducts leading into the nose. Sometimes tears cannot drain due to a blockage in the tear drainage system, often in the duct located alongside and through the nasal bone. This may result from advancing age, local inflammation, trauma, prior sinus or nasal surgery, tumors, as a side effect of chemotherapy, or other reasons. In infants and children the most common cause is failure of the tear duct to completely open before birth. Other conditions may cause excess tearing, such as dry eye, eyelid malposition (ectropion/entropion), medications, allergies, or facial palsy.