Often, optical devices require resonators with a limited set of natural frequencies and an equidistant spectrum. These requirements are satisfied by ring confocal resonators. Such resonators can be manufactured as a single monolithic element (prism) and used, in particular, as sensitive elements of miniature optical gyroscopes. As a result of external mechanical and thermal effects and imperfection of manufacturing technology, the reflecting surfaces of ring confocal resonators can be misaligned. This paper is devoted to the analysis of the effect of these misalignments on the optical properties of resonators. OOFELIE::Multiphysics software is used to calculate the deformations arising in the resonator as a result of external effects. The influence of the deformation of the resonator on its optical properties is estimated using the modified method of Fox and Lee.