Well, first, you should know that your eyes can not be watery without any reasons, it must have some reasons. First, it can be the light problem. As we know that the light in your bed is can be too strong that when you go to bed, and open our eyes to see it, it will just make the eyes be hurt. And also our eyes are so very sensitive that they will react to the stimulation from light and make your eyes watery. It is just a kind of reaction occurs to your eyes. Besides, I have to say that it can be the sign of dry eyes. When your eyes are with some irritants around you, it can be possible that you are getting the dry eyes, for dye eyes are caused by the irritants. So to make sure what happened to your eyes, you should go and see a doctor, and then can have the eye exam. You also should be careful about the dirty things. Anyway, just be careful about it. or it can lead to some other eye diseases.