Pupillary Responses in Rivalry and Amblyopia

A study of the pupillary responses to light comparing the suppressed and nonsuppressed eyes in normals during retinal rivalry, in alternate suppression in exotropia, and the normal and amblyopic eye in strabismic amblyopia is reported. Measuring pupillomotor responses with the infrared pupillograph, it is shown that the fixing or normal eye, when stimulated by light, will cause a greater pupillary contraction than the suppressed or amblyopic eye. This effect is small in normals during rivalry, and increases in magnitude as suppression and amblyopia deepens. This suggests there may be a common anatomic pathway for visual and pupillomotor suppression.