After images in peripheral vision

Year: 1974

Authors: Molesini G., Fontana A.

Autors Affiliation: Istituto Nazionale di Ottica

Abstract: A brief duration stimulus, subtending at the eye 1° diam., is flashed on a dark background, at different eccentricities along the horizontal meridian of the dark-adapted retina. The luminance of the flash is varied from the absolute threshold to 10° units above it. The events occurring after the cessation of the stimulus are described and their duration is recorded. At lower luminances the after-image is found to consist simply of a positive event, whose brightness decreases within a few seconds. As luminance exceeds a given value, which might be compared to the level of activation of lateral inhibition, the after image is found to consist of asequence of events, sharp at first and later blurred. These events find their counterpart in the Purkinje after-image and in the Hess after-image of central vision, provided the assumption is made that in peripheral vision the expansion of the time scale occurs.


Volume: 29 (2)      Pages from: 313  to: 321

KeyWords: eye; visual perception; physiological optics