On the monitor screen, three light dots 1 min arc in diameter were lined up horizontally with 60 min arc intervals from each other. Three flanking horizontal stripes 1 min of arc wide and 10 min arc long were combined in a stimulus: one stripe above or below the central dot, and the other two, respectively, below or above the end-dots with the same stripe-to-dot gap size. For subjects, the central dot appeared shifted from the horizontal line. By the panel keys, the subjects moved the central dot-stripe pattern up or down adjusting it into a position in which the straight appearance of the three-dot stimulus was established. The dot-to-stripe gap was considered as an independent variable. The perceived distortions augmented regularly with the increase of the gap from 0 to 5-7 min arc reaching its maximum and decreased monotonically approaching the zero value with further increase of the gap up to 12-15 min arc. The experimental curves were symmetrical and showed opposite signs of the illusion for opposite positions of the stripes. The vertical and oblique orientations of the combined stimuli, also, various lengths of the stimuli and stripes yielded qualitatively similar results.