of a Symposium presented at the meeting of the VI International Congress of Eye Research, Alicante, Spain, 1–7 October 1984. Organized by S.D. Klyce and R.W. Beuerman.Contributors: M.F. Refojo, I. Fatt, D. Lin, B.R. Masters, R.D. Ochsner, D.J. O'Leary, G. Wilson, J. Bergmanson, J. Friend, F.L. Leong, H. Kilp, B. Heisig-Salentin, L.L. Mannucci, F. Moro, A. Cosani, M. Palumbo, C. Kirkland, D. Lamberts, B.A. Holden, Antti Vannas, Klas Nilsson, Nathan Efron, Deborah Sweeney. Michael Kotow, Donna La Hood, Michael Guillon and A.J. Rozsa.