Since its inception, the International Research Group on Colour Vision Deficiencies (IRGCVD) has followed the policy that the Symposium Pro ceedings should be as close as possible to a complete record of the scientific content of the meeting. This policy has the advantage of providing an accurate picture of the current state of the art in research on color vision deficiencies, but it also has the disadvantage that papers typically span a wide range of quality. In this volume, however, we have instituted a system of peer review in an effort to enhance scientific quality as much as possible...