Figure 1: From pluripotent stem cells to 3D retinas. A) Human pluripotent stem cells are (B) dissociated and seeded in specific medium conditions in order to form either aggregates in 96-low binding plates, embryoid body–like structures in flasks, or pluripotent cell colonies on matrigel or other extracellular matrix (ECM) proteins. (C) Depending on the technique used, seeded cells will generate embryoid body-like structures or floating/adherent aggregates. (D) The induction of a neuroectodermal ring surrounding the aggregate drives (E) the formation of optic vesicles (patterning) which in turn invaginate to form (F) optic cups (morphogenesis). Optic cups develop inside the aggregate or are cut away. In other 2D protocols they are directly detached from the substrate. These two different modi operandi give rise to individual floating retinas (G) or to aggregate-bearing retinas (H). (G-I) These retina-like tissues can be used for modeling retinal developmental and degenerative diseases, as well as for testing cellular therapy and pharmacologic agents and gene transfer. In (I), green cells are photoreceptors, blue and pink ones are interneurons and ganglion cells respectively.