The influence of the pupillary size on the field has found little consideration. In reviewing the standard works about perimetry and glaucoma I found only three short references to this subject. Traquair1 wrote about the normal field: "The field may also be slightly diminished by a small pupil or increased by a large one if the test-object is very small, owing to the difference in the amount of light admitted to the eye. With moderately large test-objects the size of the pupil makes no appreciable difference." According to Peter,2 "A large pupil will allow rays to fall farther forward on the retina than a contracted pupil." And in comparing the glaucomatous field on different occasions Duke-Elder3 said that "every care should be taken to maintain constancy in the conditions, such as the degree of illumination, the size of the pupil, the time of the day and its