<div>lens : By changing its shape, the lens changes the focal distance of the eye. it focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances.</div>
<div>iris: The iris is a flat and ring-shaped membrane behind the cornea of the eye with an adjustable circular opening in the center called a pupil.</div>
<div>ciliary muscle : A circular muscle that relaxes or tightens the zonules to enable the lens to change shape for focusing. </div>
<div>fovea :a tiny pit located in the macula of the retina that provides the clearest vision of all. Only in the fovea are the layers of the retina spread aside to let light fall directly on the cones, the cells that give the sharpest image.</div>
<div>retina :The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain .</div>
<div>choroid : a thin vascular layer between the sclera and the retina. The choroid supplies blood to the retina and conducts arteries and nerves to other structures in the eye.</div>
<div>sclera :The sclera is the part of the eye commonly known as the “white.” It forms the supporting wall of the eyeball, and is continuous with the clear cornea. </div>
<div>vitreous humor : It is a clear gel-like substance that occupies the space behind the lens and in front of the retina at the back of the eye.</div>
<div>cornea :The cornea is the transparent part of the eye that covers the front portion of the eye. It covers the pupil (the opening at the center of the eye), iris (the colored part of the eye).</div>
<div>posterior chamber : The posterior chamber is a narrow space behind the peripheral part of the iris.</div>
<div>optic nerve :The job of the optic nerve is to transfer visual information from the retina to the vision centers of the brain via electrical impulses.</div>