[Importance of orientation on visual and neuronal resolution (author's transl)].

Spatial resolution of gratings of different orientation has been evaluated in 39 patients, by means of projected slides and by laser interference fringes. Both methods reveal a significantly higher resolution (about 12%) for vertical or horizontal bars compared to oblique ones. The similarity of findings for both methods is indicative of the neuronal origin of this orientation-dependent effect and exclude an optical origin.