Cox T A, Digre K B
Department of Ophthalmology, University of Utah Medical School, Salt Lake City.
Am J Ophthalmol. 1992 Feb 15;113(2):190-2. doi: 10.1016/s0002-9394(14)71533-8.
Pupillary constriction during forceful eyelid closure was investigated in 30 normal subjects. The right eye of each subject was filmed with an infrared-sensitive television camera in darkness before, during, and after eyelid closure. Clinically detectable constrictions were found in nine of the 30 subjects (30%). No significant correlation was found between amplitude of constriction and age of subject or baseline pupillary diameter. Forceful eyelid closure should be considered as a technique to elicit pupillary constriction in patients with a poor near response, but many subjects will have no detectable constriction using this maneuver.