New Light on the Mind's Eye: The Pupillary Light Response as Active Vision

Sebastiaan Mathot*, Stefan Van der Stigchel

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

89 Citations (Scopus)
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The eye's pupils constrict (shrink) in brightness and dilate (expand) in darkness. The pupillary light response was historically considered a low-level reflex without any cognitive component. Here, we review recent studies that have dramatically changed this view: The light response depends not only on a stimulus's brightness but also on whether you are aware of the stimulus, whether you are paying attention to it, and even whether you are thinking about it. We highlight the link between the pupillary light response and eye-movement preparation: When you intend to look at a bright stimulus, a pupillary constriction is prepared along with the eye movement before the eyes set in motion. This preparation allows the pupil to rapidly change its size as your eyes move from bright to dark objects and back again. We discuss the implications of these recent advances for our understanding of the subtle yet important role that pupillary responses play in vision.

Original languageEnglish
Pages (from-to)374-378
Number of pages5
JournalCurrent Directions in Psychological Science
Issue number5
Publication statusPublished - Oct-2015
Externally publishedYes


  • pupil size
  • eye movements
  • visual perception
  • arousal
  • SIZE

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