This slide shows a close-up of the lens and ciliary body.  The lens is a transparent structure and performs the final fine focusing of light rays. The thickness of the lens can be adjusted  by changing the tension on its attachments (suspensory ligaments)  to a structure called the ciliary body,  which possesses the ciliary muscles and small extensions called ciliary processes.  The space just behind the cornea is the anterior chamber.  The space between the iris and the lens is the posterior chamber. The space behind the lens is called the vitreous chamber or posterior segment, which is filled with a gelatinous material called the vitreous humor.