The article is devoted to the study of the optical-geometric illusion that arises when estimating the distances between the edges of objects (in particular, circles). The subject of the study is the geometric factors that affect the magnitude of the illusion. The purpose of the study is aimed at obtaining quantitative estimates of the visual illusion and revealing the nature of the dependence of the magnitude of the illusion on its geometric parameters. The research method in this work was to conduct a computer experiment (testing) with subsequent statistical analysis of the data obtained as a result of the experiment. It has been established that the dependence of the magnitude of the distance illusion on the orientation factor has a periodicity of decrease-increase in the magnitude of the illusion when the test structure is rotated, while the maximum values ​​of the illusion are recorded at such a rotation of the test object, when the subject observes it in a vertical position. It is also confirmed that the illusion of distance is linearly dependent on the diameter of the circles: the larger the diameter of the circles, the brighter the illusion.

Keywords: visual perception, visual illusions, optical-geometric illusions, Muller-Lyer illusion, distance illusion, geometric parameters of visual illusions