In the images below and on this slide, identify the heavily pigmented choroid layer surrounding the retina. Follow the choroid anteriorly and locate the ciliary body. Identify smooth muscle in the ciliary body, projecting ciliary processes, and remnants of the ciliary zonule or suspensory ligaments. Note the bilayered epithelium, inner pigmented epithelium (PE) and outer non-pigmented epithelium (NP), lining the ciliary processes. This epithelium secretes aqueous humor and attaches to the lens via the zonule fibers. At the limbus, near where the ciliary body and iris join the cornea, identify the endothelium-lined spaces of the canal of Schlemm, which drains the aqueous humor flowing through the anterior chamber.

Clinical note: Glaucoma results from the decreased outflow of aqueous humor through the trabecular meshwork and the canal of Schlemm. This elevates intraocular pressure, which can damage peripheral areas of the retina and cause progressive loss of vision. Various medications can lower the pressure and laser surgery can be used to improve drainage through the trabecular meshwork. To the right is how an individual with glaucoma sees the world.

The lens is next.