ANATOMY & PHYSIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z           HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site ciliary muscle Image credit: University of Delaware A ring of smooth muscle fibers that is responsible for changing the shape of the lens in the eye to achieve accommodation. Suspensory ligaments connect the ciliary muscle to the lens. When the ciliary muscle is relaxed the ligaments are taut, and the lens is stretched thin enabling it to focus on distant objects. When the ciliary muscle is contracted the suspensory ligaments become less taut, and the lens becomes rounder so that it focus on objects that are nearby. The contraction and relaxation of the ciliary muscle is controlled by the autonomic nervous system. Sympathetic nerve fiber stimulation causes relaxation of the muscle, whereas parasympathetic stimulation causes muscle contraction. The ciliary muscle is part of the ciliary body. Related category    • ANATOMY AND PHYSIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP