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. 1963 Nov 1;47(2):265–278. doi: 10.1085/jgp.47.2.265

The Dependence of the Photopupil Response on Flash Duration and Intensity

Mathew Alpern 1, Donald W McCready Jr 1, Lloyd Barr 1
PMCID: PMC2195344  PMID: 14080815

Abstract

The changes in pupil size were recorded by infrared pupillographic methods in response to light flashes of different durations and intensities for a 13 degree 34 minute centrally fixated circular field. For such stimuli, the threshold intensities for (rod) vision and for the pupil response were found to be about the same. The response amplitudes were related to the logarithm of the flash energy, the reciprocity law remaining valid up to about one-half second. The curve relating flash energy and pupil response was clearly divisible into two parts commensurate with the duplex character of the human retina. A similar dichotomy appears in curves relating response amplitude to response latency. Since the pupil response is determined by total flash energy, intense long flashes produce larger pupil responses than shorter (and perceptually brighter) ones of the same intensity.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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