Deterioration of vision due to contour shift over the retina during eye movements

It has been pointed out (MacKay. 1970; hlitrani. bfateeff and Yakimoff. 1971; Mitrani. Yakimoff and bfateeff. 1973) that shifts of the retinal image due either to eye movements or swift displacement of the picture a subject is looking at cause an elevation of visual thresholds. One possible explanation of this effect is connected with the assumption that movement of contours over the retina is the source of the observed visual suppression. However, two independent interpretations are possible: either the displacement of contours (i.e. their continuous movement is the cause of the suppression) or the disappearance of a given structure in one place and its appearance in another place on the retina. In an attempt to obtain more data concerning the two points of vievv we performed some new experiments with saccadic eye movements.