Iris (anatomy) surface projects as the dilator muscles. The high pigment content blocks light from passing through the iris to the retina, restricting it to the pupil. The outer edge of the iris, known as the root, is attached to the sclera and the anterior ciliary body. The iris and ciliary body together are known as the anterior uvea. Just in front of the root of the iris is the region referred to as the trabecular meshwork, through which the aqueous humour constantly drains out of the eye, with the result that diseases of the iris often have important effects on intraocular
Ciliary muscle Ciliary muscle The ciliary muscle is a ring of smooth muscle in the eye's middle layer (vascular layer) that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humor into Schlemm's canal. It changes the shape of the lens within the eye, not the size of the pupil which is carried out by the sphincter pupillae muscle and dilator pupillae. The ciliary muscle develops from mesenchyme within the choroid and is considered a cranial neural crest derivative. The ciliary muscle receives parasympathetic fibers from the short ciliary nerves that arise from the ciliary ganglion. The