optic vesicle optic vesicle the eyes begin to develop as a pair of diverticula (pouches) from the lateral aspects of the forebrain. these diverticula make their appearance before the closure of the anterior end of the neural tube; after the closure of the tube around the 4th week of development, they are known as the optic vesicles. previous studies of optic vesicles suggest that the surrounding extraocular tissues – the surface ectoderm and extraocular mesenchyme – are necessary for normal eye growth and differentiation. optic vesicletransverse section of head of chick embryo of forty-eight hours’ incubation. (optic vesicle labeled at lower right.)human embryo about fifteen days old. brain and heart represented from right side. digestive tube and yolk sac in median section. (optic vesicle labeled at center top.)detailscarnegie stage11gives rise tohuman eyesidentifierslatinvesicula optica; vesicula ophthalmicatevesicle_by_e5.14.3.4.2.2.4 e5.14.3.4.2.2.4 anatomical terminology they project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk, which goes on to form the optic nerve. additional images head of chick embryo of about thirty-eight hours’ incubation, viewed from the ventral surface. x 26