Anatomy and Embryology

Abstract

The neural ectoderm expands as the embryo grows and ultimately forms two folds with a midline groove. The folds come together, forming a tube that is commonly called the neural tube. Bilateral thickenings at the cephalic end of this tube are the beginnings of the eye. With further development the thickenings become optic pits and finally optic vesicles. The optic vesicle now harbors the cells needed to form an eye. The central portion gives rise to the sensory retina and the lateral portions to the iris epithelium and ciliary body. The outermost part of the vesicle becomes the pigment epithelium. Overlying the optic vesicle is the surface ectoderm, which eventually gives rise to the lens.