Proceedings of the Ninth symposium of the International Research Group on Colour Vision Deficiencies, held at St. John's College, Annapolis, MD, July 1-3, 1987.

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

Since its inception, the International Research Group on Colour Vision Deficiencies (IRGCVD) has followed the policy that the Symposium Pro ceedings should be a

From the 98 presentations of the XIIth Symposium on Colour Vision Deficiencies, 61 were selected after peer review and revision by the authors. In addition to t