Functional amaurosis: diagnostic value of electronystagmography.

Hysterical and malingered blindness may be distinguished from organic ocular and cortical blindness by a variety of clinical and electrophysiological tests. This report discusses the limitations of these tests and emphasizes the objective superiority of a new test which utilizes the electronystagmographic technique. This test is based on the principle that visual input blocks nystagmus induced by vestibular stimulations: the presence of nystagmus suppression will indicate that blindness is either hysterical or malingered.