Watery eye is the result of irritation or inflammation in or around your eye that causes your eye to increase tear production. One or both of your eyes may become watery. Tears make sure that debris, bacteria are cleared out as to not cause infections. Watery eye is usually caused by irritation (e.g dry eyes,  cornea abrasion) or eye infection , injury to the eye, or a common cold. Other symptoms of eye irritation, including itching, redness, a gritty feeling, and swelling of the eyelids, often happens in watery eyes.