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. Author manuscript; available in PMC: 2010 Sep 1.
Published in final edited form as: Dev Dyn. 2009 Sep;238(9):2149–2162. doi: 10.1002/dvdy.22033

Figure 2. Morphogenesis of the anterior segment.

Figure 2

The anterior segment develops from ocular surface ectoderm (blue), neural ectoderm (green), and neural crest and mesoderm mesenchyme (orange). (A) Anterior segment morphogenesis is initiated when direct interaction of the distal optic vesicle indices formation of the lens placode within the overlying ocular surface ectoderm. (B) The lens pit forms by invagination of the lens pit while the optic vesicle is concurrently converted in the optic cup. The inner layer of optic cup will form the retina, the outer layer will form the retinal pigmented epithelium, and the anterior rim of the optic cup will contribute the epithelial components of the ciliary body and iris. (C) Loosely arranged mesenchyme migrates between the newly formed optic vesicle and anterior optic cup and the overlying presumptive cornea. Eyelid folds emerge as the first morphological evidence of eyelid development. Key: C, cornea; E, eyelid; EF, eyelid folds; L, lens; LP, lens placode; LV, lens vesicle; M, mesoderm; OSE, ocular surface ectoderm; OV, optic vesicle; P, periderm; Pit, lens pit; R, retina; PRE, retinal pigmented epithelium