初中物理课本指出，凸透镜又叫会聚透镜，凹透镜又叫发散透镜．至于光线怎样传播属于会聚，怎样折射属于发散，课本里没有具体论述．因此，往往使人对此问题感到抽象、模糊，甚至误解．有不少人简单地认为，凡是光线相交干一点属于会聚，光线不相交于一点都属于发散．其实，这? The junior high school physics textbook points out that the convex lens is also called converging lens, and the concave lens is also called divergent lens. As for how light is transmitted as a converging and how refraction is divergent, there is no specific discussion in the textbook. Therefore, people often feel abstract, vague, and even misunderstood. There are many people who simply think that where light intersects one another is a convergence, light does not intersect at one point and it is divergent. In fact, this?