This book represents the proceedings of the Sixth World Congress of the International Retinitis Pigmentosa Association (IRPA), Dublin, Ireland, July 20-22, 1990. It is intended for all research workers and ophthalmologists interested in the etiologies and diagnosis of inherited degenerative retinopathies. The book contains 22 original papers, many of which are genetically oriented. The genetic focus is due to the fact that highly significant progress in genetic research has been made over the last few years. Topics addressed in the book include proteins of the visual transduction cycle and their effect in the etiologies of RP, identification of more mutations, and new technologies for genetic analysis. The new technologies, in particular, will interest specialists in molecular genetics and researchers seeking information about more clinical applications and the implications of research of inherited retinopathies.