Colour Vision Deficiencies XI

The eleventh Symposium of the International Research Group on Colour Vision Deficiencies (IRGCVD) was held 20-23 June 1991 in Sydney, Aus­ tralia, ably hosted by local organizer Stephen Dain. A total of 35 talks and 10 posters were presented. Papers based on 37 of these presentations are included here, in Colour Vision Deficiencies XI. The scientific program featured sessions on three special topics, with each topic highlighted by an invited speaker. The opening session on the Genetics of conge