Upon differentiation, undifferentiated pluripotent stem cells (A) can be directed towards retinal cell fates following several steps that resemble normal developmental stages. First, they develop into a neural epithelium (B) that evaginates to form optic vesicle-like structures (arrows in C), and finally optic cup-like structures (arrows in D). The retinal progenitors can then differentiate into RGCs (E). The arrows in E show fluorescently-labeled RGCs (green) in a 10-day retinal organoid. Abbreviations: OV: optic vesicles, OC: optic cups, RGC: Retinal Ganglion Cells. Scale: 100 microns