Eyes water because , while driving the rate at which the eye dries up increases , hence of rate of secretion of tears also goes up. since we are not driving at a constant speed there is a mismatch between the tear secretion and eyes drying up . our body always tries to over perform. this over secreted tears is too much to handle by the normal
tear route from the eyes to the nose. hence the excess tears overflow leading to watering.So it is a normal process.Dont worry about this.Your eyes are normal.