The visual processes in the human retina begin with absorption of photons from light. This light energy is converted into electrical stimuli in a series of enzymatic steps which initiates neural responses to light. Therefore, any structural and functional abnormalities in these molecules will likely interfere with signal transduction which may ultimately lead to blindness. A new era began in 1990 with an ultimate goal of redefining and developing new treatments for the photoreceptor disorders by identifying mutations in the genes encoding phototransduction cascade enzymes. As a result of this intense investigation around the world, mutations have now been identified in eight genes, in several retinal dystrophies. Almost all of these genes encode signal transduction enzymes and all are highly expressed in photoreceptor cells. This effort has been further aided by gene disruption technology. Although there are many puzzles that need to be solved, these approaches have given some insight into the genetic eye disorders and will undoubtedly improve our understanding of inherited eye disorders in the future. This improved knowledge may eventually lead to prevention or a cure.