Binocular disparity in visual evoked responses. Clinical evidence in normal and stereoblind subjects

The authors have utilized a binocular flat or stereoscopic pattern (grating) to record visual evoked responses (VER) in normal and strabismic subjects. The aim was to find an electrophysiological correlate with the degree of binocular interaction in these subjects. The perception of the grating as tridimensional or flat derived from the disparity obtained with Polaroid filters placed in front of the eyes. In normal subjects, the results demonstrated a significant increase of VER amplitude during tridimensional perception of the pattern. In strabismic subjects the electrophysiological response was not correlated with the binocular conditions.