It is the only visible part of the uveal tract, which is visible in front of the eye lens.
Its location divides the space between the cornea and lens to the anterior chamber and the posterior chamber of the eye. In the center of the iris is a circular hole – pupils (pupil). Peripheral edge grow together with the ciliary bodies, where the cornea creates chamber angle. From peripheral edges extend thin fibers, which are clamped on the sclera and the cornea. Between the individual fibers are spaces that communicate with the anterior chamber and have their function in aqueous humor outflow. The color of the iris depends on the amount of pigment in the so-called Chromatophores.