| Citation | Mollon is distinguished for his work on visual perception, especially the perception of colour, which he has studied by both psychophysical and neurobiological methods. In a field of research where technical and conceptual excellence are essential, he is an international leader. By purely psychophysical experiments he discovered several exceptions to Weber's Law as it applies to radiance and chromaticity, indicating that post receptoral as well as receptoral processes govern chromatic sensitivity. This work led to an influential shift in thinking about chromatic sensitivity and to an understanding of the importance of post receptoral processes. In work with Bowmaker and Jacobs, recognized by an international award from the Rank Prize Fund, they demonstrated the relationship between the carefully measured characteristics of colour vision in several monkeys and the properties of individual cone receptors from the eyes of the same monkeys. Their results are of fundamental importance to our understanding of the nature of dichromacy and anomalous trichromacy. Mollon also proposed a model, now confirmed at the molecular level, of how X-chromosome inactivation allows the heterozygous female monkey to gain an extra dimension of colour vision. He also argued that dichromacy, such as red-green colour blindness, should be advantageous in breaking certain forms of camouflage and demonstrated this to be so in human observers, providing for the first time a sound reason why variations in colour vision can be an advantage in social animals like primates. He has also made notable contributions to the study of the history of visual science, for example, by showing how the understanding of physical optics in the eighteenth century was held back by mistaken models of sensory transduction. |