DISTORTIONS IN 2-DIMENSIONAL VISUAL SPACE-PERCEPTION IN STRABISMIC OBSERVERS

Amblyopic subjects were asked to memorize circles of different radii ( 2, 4 and 6-degrees), and then to reconstruct them monocularly with eac h eye, point by point (12 points per circle). The resulting two-dimens ional maps of visual space showed considerable distortions, including expansion, shrinkage and torsion of specific regions of the visual fie ld of the amblyopic eye, but not the normal eye. Based on the differen ces between the two eyes, we computed complex two-dimensional patterns (gratings, checkerboards, optotypes, written text, natural scenes) as ''seen'' monocularly with the amblyopic eye. These reconstructed patt erns were then compared with drawings of the same patterns observed th rough the amblyopic eyes of the same subjects. The reconstructed patte rns only partially reflected the actual perception for the amblyopic e yes. The compensation of complex, globally-extended scenes in comparis on to the distortions obtained by local, punctate settings probably re flects cooperative interactions occurring at higher brain levels.