part_of part of part of develops from developmentally induced by tissue neurectoderm eye primordium ectoderm-derived structure optic vesicle http://upload.wikimedia.org/wikipedia/commons/e/e0/Gray863.png Genes: Six3, Pax6, Rx1 are expressed together in the tip of the neural plate [ISBN:9780878932504 "Developmental Biology"]. Development notes: During subsequent develop- ment, the optic vesicle invaginates and becomes a two-layered structure with an inner neural retina and outer retinal pigment epithelium. As soon as the developing optic vesicle makes contact with the overlying ectoderm, it induces the ectoderm to thicken and form the lens placode [PMID:16496288] chordamesoderm immature eye