An analysis of the morphology, amplitude and latency of visual evoked potentials to photic flashes and reversing checkerboard pattern is being conducted. Normative data have been collected from normal individuals, predominantly of 20-50 years. Visual evoked responses also have been examined in patients with various neurological disorders. Prolonged latencies of the major positive peak have been noted in patients with multiple sclerosis and neurological disorders. A half visual field stimulation is used to evaluate the retrochiasmatic visual pathway in normals and patients with various neurological disorders.