Dry eyes. Dry eyes can be caused by a decreased production of tears, or by a decrease in the amount of one or more of the tear components (water, mucus, oil). If the mucus or oil production is diminished, the water part of the tears evaporates too quickly and the eye becomes irritated. This signals the tear gland to produce more water, which does not stick to the eye and ends up on your cheeks.
Dry eyes. Depending on where you live, the most likely reason why you tear is dry eye syndrome. The extra tears are your body's response to the dryness. The first step is to use artificial tears for the dryness. Other options include punctal plugs, restasis. If the tearing is not improved with artificial tears, you should see your eye md to make sure the tearing is not due to another condition.