Contents >> what is Iris? structure of Iris, nerve supply of Iris. Today I am telling you about Iris which is an important part of our eye.so we should know about it please read the article fully learn about the Iris, structure of Iris, Nerve supply of Iris. Location of Iris The iris lies in front of the le ns and the ciliary body.It separ ates the anterior c ha mbe r from the posterior chamber .Pupil is situated slightly nasal si de of center.Its periphe ry or root is attached to an terior e nd of the ciliary bod y. Anter ior surface of the iris is divided into two zone s - 1.centr al p upilary zone 2.peripheral cilia ry zone . There junction is a circula r ridge ,call ed " collarette" which marks the embryonic site of the mi nor vascula r circle of iris, f rom wh ic h the embryonic pupil l ary membrane originated.the ciliary zone is marked by man y ridges a nd crypts ,but the pupillary zone is relative ly fla t.