Yes, generally speaking, when you have reading the bus which is moving forward, it will do harm to your eyes. Of course, if you just have this case for one time, it does not matter. But you also should know why they are harmful. When you have reading in the bus which is moving, it will become harder for your eyes to focus on the point. So you have to focus on the point in a tough way. In a long time, it can lead to eye strain. Then that can also cause pink eyes, or dry eyes. So anyway, you are not supposed to read book in a moving bus. Besides, you should also pay attention to the position you have reading. It can play an important role in the eyesight.