[Skip to Navigation]
Article
October 15, 1932

THE REACTION TIME OF THE NORMAL PUPIL: SECOND COMMUNICATION

Author Affiliations

CHICAGO

From the Department of Ophthalmology and the Department of Physiology of the Michael Reese Hospital of Chicago.

JAMA. 1932;99(16):1334-1336. doi:10.1001/jama.1932.02740680030008
Abstract

In a previous communication,1 the reaction time of the normal pupil was established by cinematographic means. Briefly, it was found that when light is flashed on a normal eye that is accommodated for the dark, there occurs a latent period of 0.1875 second before the pupil begins to contract. Then there follows a rapid primary contraction for 0.4365 second at the rate of 5.48 mm. per second. This is succeeded by a secondary contraction of 0.3125 second at the slower rate of 1.34 mm. per second. These experiments were conducted on normal young persons, an 8 ampere arc light being used for illumination, and the pupillary play being recorded by a spring-driven cinematographic camera of constant speed. The films thus obtained were projected on a screen, frame by frame, and the pupillary diameters measured in the projected pictures. The relationship to the corneal diameter, which was measured in the

×