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
Long posterior ciliary arteries pupillary margin, where they form a second (incomplete) arterial circle, the circulus arteriosus minor. The long posterior ciliary arteries supply the iris, ciliary body and choroid. Long posterior ciliary arteries The long posterior ciliary arteries are arteries of the head arising, together with the other ciliary arteries, from the ophthalmic artery. There are two in each eye. They pierce the posterior part of the sclera at some little distance from the optic nerve, and run forward, along either side of the eyeball, between the sclera and choroid, to the ciliary muscle, where they divide into two branches. These form an