The article discusses the features of light-signaling devices and their characteristics. The design elements of such devices and their optical systems (OSs) are described. The features of the use of optical elements for obtaining various radiation patterns of LEDs in space are analyzed. The problems and prospects of computer modeling of optics, which are used to form the required light distribution in LED lighting devices, are considered. The article discusses a numerical Monte Carlo simulation method that allows to organize the simulation of ray tracing in OSs. The Monte Carlo ray tracing procedure is analyzed. A scheme for modeling of the light propagation in an OS, based on the Monte Carlo method, which forms the basis of the TracePro software package for optical design, is considered. A research of the methods for calculation of OSs based on Fresnel lenses, calculation and computer simulation of such a lens were conducted. 3D models of the device and Fresnel lenses have been developed using the computer-aided design system KOMPAS-3D. For the given properties of LEDs, selected materials, and ray tracing conditions, the light distribution of the device has been calculated and analyzed in TracePro. The calculation and modeling of the OSs based on Fresnel lenses made it possible to obtain the acceptable results in the form of light distribution that meets the requirements for light signaling purposes. This model can be recommended for prototyping and studying the characteristics of experimental samples.