Embryologic origin of the ocular tissues. 1, Vitreous body; 2, ciliary muscle; 3, ciliary body epithelium; 4, zonular fibers; 5, corneal endothelium; 6, corneal stroma; 7, corneal epithelium; 8, iris sphincter; 9, iris dilator; 10, lens; 11, iris stroma; 12, trabecular meshwork; 13, conjunctiva; 14, inferior oblique muscle; 15, inferior rectus muscle; 16, medial rectus tendon; 17, medial rectus muscle; 18, medial rectus muscle sheath; 19, inferior orbital bones; 20, optic nerve sheath; 21, optic nerve; 22, bulbar sheath; 23, sclera; 24, choroid; 25, neurosensory retina and retinal pigment epithelium; 26, superior rectus muscle.