[J.J. a daltonic painter]

Mr. J.J., painter, has been a professional artist for thirty years. On clinical examination of the color vision by pseudo-isochromatic plates, City University Colour Vision Test, standard and desaturated Panel-D 15, Farnsworth 100-hue test and Nagel's anomaloscop evidenced a typical hereditary deuteranopia. Neverless, the recognition and the denomination of coloured samples, presented singly or in simultaneous chromatic contrast, evidenced only a few errors. In an interview, the subject explained his difficulties with colours, mainly with green, and the procedures used to avoid mistakes in painting: knowledge of the names of colors written on tubes; precise order of arranging the tubes; use of a palette restricted to some basic hues, avoiding green. The subject artistic technique is based on drawing, on better perceived colours (i.e. the blues) and on value contrasts. He also enumerated his difficulties with colours in casual situations: clothes, traffic, food. Some reproductions of the works of the painter illustrate this study.