视束病变不常被认识。Smith在100例同向性偏盲中,见之仅3％;他谈到,以视野计诊断视束病变十分困难,本症诊断之所以少,正反映了这一困难。Smith的诊断标准是,有“极不对称的偏盲、视动反应阴性、Behr氏瞳孔和邻近结构神经症状的证据”。作者强调,伴同神经症状所起的作用是这样的重要,以致缺少了它们,视束病损的可能性竟常 Visual tract lesions are not often recognized. Smith, of the 100 cases of homonymous hemianopia, saw only 3% of cases. He noted that it is very difficult to diagnose optic tract lesions by field of vision. The small number of diagnoses of this disease reflects this difficulty. Smith’s diagnostic criteria are “extremely asymmetrical hemianopia, negative visual acuity, evidence of Behr’s pupil and neurological symptoms of adjacent structures.” The authors emphasize the importance of the same neurological symptoms as the lack of them, the possibility of visual impairment of the beam