几何光学是光学学科中以光线为基础，研究光的传播和成像规律的一个重要的实用性分支学科。在几何光学中，把组成物体的物点看作是几何点，把它所发出的光束看作是无数几何光线的集合，光线的方向代表光能的传播方向。-Geometrical optics is the optics of light-based disciplines to study the laws of light propagation and imaging is an important practical branches. In geometric optics, the composition of the object point as a geometric object point, the beam as it issued numerous geometric light collection, representative of light in the direction of light propagation direction.