The 13th biennial Symposium of the International Research Group on Colour Vision Deficiencies was held from 27 July to 30 July, 1995, in the splendidjin de siecle Theatre Saint Louis, in Pau, France. A total of 80 papers and posters were presented during the four days, of which 56 have been selected for inclusion in this volume. Each has been reviewed by two of the Editors. Additionally, in numerous cases in which specialized knowledge was called for the Editors asked for external help; their assistance is acknowledged below. While Pau now exists largely on agriculture and, more recently, oil...