The back two-thirds of the eye that includes the anterior hyaloid membrane and all of the optical structures behind it: the VITREOUS HUMOR; RETINA; CHOROID; and OPTIC NERVE.

The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.

The most anterior portion of the uveal layer, separating the anterior chamber from the posterior. It consists of two layers - the stroma and the pigmented epithelium. Color of the iris depends on the amount of melanin in the stroma on reflection from the pigmented epithelium.

A ring of tissue extending from the scleral spur to the ora serrata of the RETINA. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion.

The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.