The article discusses the problems associated with the study of the occurrence of systematic errors in visual perception, manifested in the form of illusions. The level of existing technology demonstrates a lack of technical means and methods aimed at studying visual perception in conditions of the occurrence of visual illusions. In this regard, the authors proposed a testing methodology and an automated system that allows us to systematize the process of studying visual illusions. Based on the proposed model, a study of the visual illusion of intersection was carried out (Poggendorff illusion), which occurs when the visual perception of a diagonal line partially passing behind an opaque object. The dependence of systematic errors that arise when determining the location of the output segment, relative to the input, on the geometric parameters and configurations of figures causing the illusion was studied.