Painful, irritated eyes cause intense tearing up. It seems contradictory that watery eyes can be a symptom of "dry eyes". This is because "dry eye" itself is a collective term that refers to any abnormality of the tear film, whether it is insufficient production or an imbalance in tear production. When the surface of the corneal epithelium becomes irritated due to a lack of tear supply, the eye's natural response is to produce "reflex tears", to compensate for the problem. However, excessive production of reflex tears can exacerbate the tear film problem.