<P> The refractive index of the eye's lens system allows the eye to produce sharply focused images . For example, geometrical optics show that as a distant object is brought closer to the eye, the focus of the object becomes blurrier in the plane behind the retina; however, as a result of the increase in the refractive power of the eye, this image becomes clear . The refractive power mainly resides in the cornea, but the overall refractive power is achieved by the actual lens changing its shape . </P> <P> In order to fixate on a near object, the ciliary muscle contracts around the lens to decrease its size . The suspensory zonules of Zinn relax and the radial tension around the lens is released . This causes the lens to form a more spherical shape achieving a higher level of refractive power . </P> <P> When the eye focuses on distant objects, the lens holds itself in a flattened shape due to traction from the suspensory ligaments . Ligaments pull the edges of the elastic lens capsule towards the surrounding ciliary body and by opposing the internal pressure within the elastic lens, keep it relatively flattened . </P> <P> Opposite of fixating on a near object, the ciliary muscle relaxes and the diameter of the lens increases to increase the lens' size . The tension along the suspensory ligaments is increased to flatten the lens and decrease the curvature and achieve a lower refractive power . </P>

Which of the following is not a component of the accommodation response