Special CPM Seminar

Old news and new news about single-photon sensitivity in human vision

Philip Nelson

University of Pennsylvania

It is sometimes said that “Our eyes can see single photons.” I'll begin by finding a more precise version of that claim and reviewing evidence gathered for it up to around 1985 in two distinct realms, those of human psychophysics and single-cell physiology. Finding a single framework that accommodates both kinds of result is then a nontrivial challenge, and one that sets severe quantitative constraints on any model of dim-light visual processing. I'll present a new model that accomplishes this task, and compare it to recent experiments.