Fig. 1. Schematic drawing of development of the optic vesicle, optic cup, neurosensory retina, and retinal pigment epithelium (RPE). ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer. (Dowling JE: The Retina. An Approachable Part of the Brain. Cambridge, MA: Belknap Press of Harvard University Press, 1987.)