In the paper an attempt is made to justify the importance of geometrical language (especially metric space models) for the description of visual perception processing. The tradition to use geometry for the description of psychophysiological processes goes back to a Newtonian color circle. At present there are many examples of such models, as well as of examples from other areas of mathematics. However, we want to justify a position, that geometrical language is not simply one of formal languages used for the description of visual perception phenomena. We'll try to represent it as the approach, which includes both the formal description of psychological phenomena and neurophysiological mechanisms, as well as experimental techniques of research into these phenomena and mechanisms.