Binda, P. & Murray, S. O. (2015).

Keeping a large-pupilled eye on high-level visual processing,Trends Cogn Sci.

The pupillary light response has long been considered an elementary reflex. However, evidence now shows that it integrates information from such complex phenomena as attention, contextual processing, and imagery. These discoveries make pupillometry a promising tool for an entirely new application: the study of high-level vision.