When there are some foreign objects enter into our eyes, our eyes will produce large quantity of tears to wash the foreign objects out as a self defense reaction. You can wash your hands and then open your eyelids with your fingers. If you can't see any foreign objects in your eyes, you can ask someone to find it out for you. Then get the objects out of your eyes, you eyes will not tear again.
You can put some artificial tears into your eyes to wash your eyes. When our eyes are very dry, our eyes will produce more tears to lubricate your eyeballs. You can have your eyes checked first to see what caused the symptom and whether you need some special treatment or not. Sometimes, environmental factors such as wind or smokes can be the triggers of watery eyes. But the symptom will disappear few days later. Hope you will be fine soon.