Well, it is normal for many people to have this kind of situation just like you. So you do not need to worry about it, and it can be fine. Generally speaking, when you go outside where there is strong sun, and the light is so strong that when you open eyes to see it, and the light gets into your eye ball. And of course, our eyes are so very sensitive that they will react to the stimulation from sun light. In that way, so it will just make the eyes hurt. And we can say that it is the reaction to the strong light. On the other hand, there is also because of the irritants in the air outside. And when you go out, your eyes are easy to be infected by them. For your situation, you can just wear sunglasses to protect your eyes.