Engineering Physics Annotation << Back Synthesis of a Thermal Imaging Lens With Variable Focal Length Bezdidko S.N. The article “Synthesis of optical systems with minimal angles of incidence of rays on a surface” [1] outlined a new approach to constructing an initial optical system that satisfi es the specifi ed requirements of the technical specifi cations. The use of this approach has proven its effectiveness in the construction of various types of optical systems, therefore in the proposed article we will show the use of this approach in the construction of the initial scheme of a thermal imaging lens with a variable focal length. It should be immediately noted the most important feature of this approach - the constructed systems have minimal higher-order aberrations. This ensures a simpler procedure for further optimization of these systems, since with small higher-order aberrations, optimization programs have less local limitation determined by the magnitude of higher-order aberrations [2]. Keywords: design of optical systems, theory of aberrations, angles of incidence of rays on the surfaces, synthesis, optimization. DOI: 10.25791/infi zik.9.2024.1422 Pp. 03-20.