The<unk>  (pupil<unk>  muscle, pupillary<unk> , radial muscle of iris, radiating fibers), is a smooth muscle of the eye, running radially in the iris and therefore fit as a<unk> . The pupillary<unk>  consists of a spokelike arrangement of modified contractile cells called myoepithelial cells. These cells are stimulated by the sympathetic nervous system. When stimulated, the cells contract, widening the pupil and allowing more light to enter the eye.
Iris dilator muscle
Iris sphincter muscle
Oculomotor nerve
Iris pigment epithelium
Corneal endothelium
Scleral lens
Choroid glomus
Corneal limbus