Pupillary response or dilation of the pupil is a physiological response that varies the size of the pupil of the eye via the iris dilator muscle. It can have a variety of causes. It may be an involuntary reflex reaction to exposure to light. Or it may indicate interest in the subject of attention or indicate sexual stimulation. The pupils contract immediately before someone falls asleep.
The latency of pupillary response (the speed at which it occurs) increases with age.
- Hess, Eckhard H.; Polt, James M. (5 August 1960), "Pupil Size as Related to Interest Value of Visual Stimuli", Science, 132 (3423): 349, doi:10.1126/science.132.3423.349 Check date values in:
- Lowenstein, Otto; Feinberg, Richard; Loewenfeld, Irene E. (April 1963), "Pupillary Movements During Acute and Chronic Fatigue: A New Test for the Objective Evaluation of Tiredness", Investigative Ophthalmology, St. Louis: C.V. Mosby Company, 2 (2): 138–157 Check date values in:
- Baker, Lynn Erland (1938). "The Pupillary Response Conditioned to Subliminal Auditory Stimuli". Ohio State University.
- Podolak, Edward; Feinberg, Richard (September 1965), Latency of pupillary reflex to light stimulation and its relationship to aging, Federal Aviation Agency, Office of Aviation Medicine, Georgetown Clinical Research Institute, p. 12 Check date values in:
- Ishikawa, S.; Naito, M.; Inaba, K. (1970), "A new videopupillography", Ophthalmologica, 160 (4): 248–259 Check date values in:
- Janisse, Michel Pierre (1977). Pupillometry: The Psychology of the Pupillary Response. Halsted Press. ISBN 0470991739. Check date values in:
- Dilated fundus examination
- Iris dilator muscle
- Iris sphincter muscle
- Pupillary light reflex