Dr. MacLeod's empirical and theoretical contributions include some of the most striking advances in vision science in the second half of the twentieth century. Among his many contributions, MacLeod (with Boynton, 1979) developed a constant luminance cone excitation chromaticity space. The MacLeod-Boynton chromaticity diagram is widely used, and has become the preferred way of expressing chromatic discrimination data. The Commission Internationale de l'Eclairage will include a version of the MacLeod-Boynton chromaticity diagram in its new physiologically based colorimetric system. With Eisner (1980), he provided experimental evidence that the S-cones do not contribute to flicker photometric sensitivity. With Williams and Hayhoe (1981), MacLeod psychophysically mapped the S-cone distribution in the fovea. With Webster (1983, 1987), MacLeod analyzed individual differences in cone receptoral spectral sensitivities before molecular genetics provided a cellular basis fori functional polymorphism. The conclusions of the Webster-MacLeod analysis are concordant with modern molecular genetic studies.
André Roth created the Roth 28 Hue test for ophthalmological examination, and developed and standardized a sophisticated diagnostic set of tests based on color metrics for acquired color vision deficiencies. He developed an anomaloscope specially for the investigation of acquired and inherited color vision deficiencies in ophthalmology. As director of the Geneva University clinic, he has studied most eye diseases in which acquired color deficiencies play a significant role. Work for the IRGCVD and later ICVS was a significant part of his professional life. Together with Guy Verriest (the first President of the Society, for whom the medal is named), André belonged to the clinically oriented group, which recommended a separation of the IRGCVD from the AIC, to give ophthalmologists, physiologists and other clinicians a scientific home and a connection to color science. Soon after the death of Guy Verriest he took over the presidency of the Society from Wolfgang Jaeger and carefully led its further development, with expanded emphasis of genetic, molecular biological, physiological, and psychophysical research.
If the field of colour vision was itself a rainbow, then Professor Mollon's contributions cover nearly its full spectrum, including the isolation and elucidation of basic chromatic coding mechanisms and the constraints that they impose on human (and more generally primate) visual performance, the genetic basis of spectral coding mechanisms, the ecological influences on and evolutionary orgins of chromatic discrimination. He has been instrumental in the design of several new colour vision tests and has extensively exploited abnormal models, both congenital and acquired, to further our understanding of normal mechanisms. He is especially appreciated for his keen and profound sense of the history of science, in particular with respect to the field of colour vision.
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