The causal gene for a congenital form of cone-rod dystrophy POC1B and the gene causing Oguchi disease GRK1 are involved in the functioning of photoreceptor synapses and light-dependent deactivation of rhodopsin respectively [169–171], which suggests that photoreceptor-related signaling is involved in baseline refractive eye development. Here, GRK1 is linked to Oguchi disease.