Mathot, Siebold, Donk, and Vitu (in prep). Large Pupils Predict Goal-driven Eye Movements.
These images are modified from
Tkačik, G., Garrigan, P., Ratliff, C., Milčinski, G., Klein, J. M., Seyfarth, L. H., … Balasubramanian, V. (2011). Natural images from the birthplace of the human eye. PLoS ONE, 6(6), e20409. doi:10.1371/journal.pone.0020409