Eye-head coordination in homonymous hemianopia.

Quantitative studies of latencies and trajectories of eye-head movements during visual search and fixation in patients with occipital hemianopia show that (1) the latency of head movement is bilaterally increased, with significantly greater delays in movements toward the blind side; (2) the compensatory eye movements (CEMs) during head movements toward the blind side have increased velocity; (3) these CEMs entail a non-vestibular anticipatory component; and (4) head movements toward the blind side are comprised of multiple steps similar to staircase eye movements documented in previous studies. Hemianopic patients seemingly simplify search and fixation strategies by minimizing or entirely eliminating head movements and relying on eye movements instead.