We study vision – all aspects of vision, in any accessible creature. We have used techniques ranging from anatomy, to electrophysiology, to behavioral methods. We have studied topics from recording responses of single neurons to spectral lights, to impact of environmental light on aesthetics of museum-going, to sex-linked differences in basic visual functions, to categorization of objects seen under degraded viewing conditions. Always, our approach is ultimately based on the biology of the visual system. At present we are concentrating on behavioral (a.k.a. psychophysical) studies of sex-linked variations in vision, and detectability of objects when viewing is less than optimal.

These studies derive from a program we undertook some three decades ago: creation of a battery of tests to measure many aspects of vision: spatial and temporal resolution, and acuity; color vision, from discrimination to magnitude estimation of color appearance; binocular vision, stereopsis, and stereo-acuity; motion detection; pigmentation of iris and skin. A rigorous test protocol was implemented: the same apparatus continues to be used, and most systems are computer-controlled to avoid run-time errors; where applicable, psychophysical procedures are free of observers’ responses biases (forced-choice methods); most participants complete the entire battery, which takes at least fifteen sessions. The result is that we now have a large, comprehensive, high-quality database, from which we are extracting a wide range of comparisons of visual functions; one advantage of having data from the entire battery is that any differences we find cannot be based on uncontrolled differences in other visual functions. For example, we have shown that the visual systems of males and females are not the same: there are significant differences in spatial and temporal resolution, as well as in color vision (perceived hue and saturation); while the male-female differences are sometimes small, they are important because they imply real differences in the “wiring diagrams” of the visual system.

Our group includes graduate students (both Master and Doctoral candidates), and undergraduate research assistants, for whom the experience is valuable for academic reasons as well as for potential “references.”