SPATIAL DISORIENTATION WITH HOMONYMOUS DEFECTS OF THE VISUAL FIELD

Abstract
Patients with homonymous hemianopia differ in the degree to which they are aware of their defects. When the lesion is infrageniculate, e. g., in the optic tract, the existence of partial blindness is recognized, and a compensatory turning of the head and eyes develops. If an adjusted attitude is not established, the patient stumbles against objects on the blind side and overlooks words and letters in reading. The reading difficulties are less likely to be apparent in longer sentences because the resulting change in meaning arouses the attention of the patient and he adjusts his gaze until the proper field of vision is achieved. In some cases of lesions of the suprageniculate pathways the visual disturbances may be complicated by agnostic factors. The patient shows faulty comprehension of visual objects and consequently is unable to compensate automatically for his defects. Kleist distinguished between visual "object agnosia," in which the forms