[Skip to Navigation]
April 1958

Differential Threshold Measurements on the Light Reflex of the Human Pupil

Author Affiliations

Soesterberg, Netherlands
Instituut voor Zintuigfysiologie RVO-TNO, Kampweg 5, Soesterberg (Dr. Bouman). Nederlands Gasthuis voor Ooglijders, University Eye Clinic, Utrecht (Dr. Schweitzer).

AMA Arch Ophthalmol. 1958;59(4):541-550. doi:10.1001/archopht.1958.00940050097012

1. Introduction  Before discussing the threshold of the pupil reflex, it seems necessary to state that its value depends mainly on intrinsic qualities of the individual nervous system and, in some degree, on the mechanical properties of the iris tissue.We know very little about those nervous factors, but it is a fact, common to the clinician and confirmed by experiments, that some persons require a much higher energy of light to respond with a contraction of their pupils than do others, while in abnormal circumstances, as, for example, in Adie's syndrome, the insensitivity of the pupil to light stimulation is pathognomonic.As to the iris tissue, it seems probable that the amplitude of contraction and therefore its apparent threshold is smaller in old than in young persons at any given amount of stimulation, owing to sclerotic changes in the mesodermal tissue layers of the iris.It is evident that

Add or change institution