Pupillography, as the name suggests, is the measurement and recording of the diameter of the pupil. Prior to 1958 photographic methods were used almost exclusively. In that year, Lowenstein and Loewenfeld described their electronic pupillograph.1 This facilitated recording much more data than was previously considered practical.
With the advent of electronic pupillography, pupillary reflex responses could be obtained from a wide variety of stimuli. The pupillograph has been used both for studies in vision research and for clinical investigations. The instrument we have developed is a binocular infrared pupillograph intended primarily for use in research.
The instrument consists of three assemblies: the head support (A), the optical scanning system (B), and the electronic system (C) (Fig 1). The optical axis of the scanning system is 20° below the horizontal. This makes it possible for the subject to fixate on a target by looking straight ahead and leaves adequate
CLARKE WB, KNOLL HA, NELSON C. A Binocular Infrared Pupillograph. Arch Ophthalmol. 1966;76(3):355-358. doi:10.1001/archopht.1966.03850010357009