I studied applied math at Harvard (BA '75) and vision at Cambridge (Physiology PhD '81), with Campbell and Robson. At Minneapolis ('80 postdoc with Legge), Syracuse ('81-'95 professor), and NASA Ames ('87 sabbatical with Watson and Ahumada), I worked on visual requirements of reading and mobility, on visual testing (e.g. the Pelli-Robson Contrast Sensitivity Chart), and on characterizing the limits of visual perception. Since 1995 I've been Professor of Psychology and Neural Science at New York University, studying letter and object recognition and beauty.