sädekehälihas

The ciliary muscle is a ring of smooth muscle in the eye's middle vascular layer, the uvea. It controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humor into Schlemm's canal. The ciliary muscle is composed of three parts: the ciliary body, the ciliary ring, and the ciliary processes. It is innervated by the parasympathetic nervous system via the oculomotor nerve. When the ciliary muscle contracts, it moves forward and inward, relaxing the suspensory ligaments that hold the lens. This causes the lens to become more rounded, increasing its refractive power and allowing the eye to focus on near objects. When the ciliary muscle relaxes, the suspensory ligaments are tightened, flattening the lens and allowing the eye to focus on distant objects. Dysfunction of the ciliary muscle can lead to various vision problems, including presbyopia, accommodative spasm, and cycloplegia.