The diploma thesis deals with the optical design of low beam LED reflector. The thesis aims to optimize the existing low beam LED reflector with an emphasis on achieving a legal and homogeneous light distribution. The theoretical part contains the essay of light sources and optical systems used in headlights, as well as the description of the production technology of LED reflector for different polymeric materials. The experimental part presents a detailed methodology for the optical design of low beam LED reflector in the company software. The thesis also contains a description of the original low beam LED reflector and its problematic parts. The optimization of LED reflector was performed by changing its construction and by the replacemen...