This volume foxuses on the status of Ca2+ ions in regulation of phototransduction, light adaptation and the recovery phase in vertebrate photoreceptors. Particular emphasis is given to Ca2+-binding proteins and their targets, among them particulate guanylate cyclases, GPCR-coupled kinases and cyclic nucleotide-gated cation channels. The book also expands our understanding of events invovling Ca2+ in the retinal pigment epithelium, in synaptic transmission and secondary retinal neurons. A significant part of the book is dedicated to the role of Ca2+ in invertebrate phototransduction, the best-studied phospholipid-mediated signal transduction pathway. Several chapters explore association of gene defects with human retina disease and the generation of animal models of retinal degeneration.