pupillary sphincter(n = noun.body) musculus sphincter pupillae - a ring of smooth muscle surrounding the iris;
is a kind of anatomical sphincter, sphincter, sphincter muscle
is a part of eye, oculus, optic

anal sphincter, anatomical sphincter, bladder sphincter, cardiac sphincter, musculus sphincter ani, musculus sphincter ani externus, musculus sphincter ani internus, musculus sphincter ductus choledochi, musculus sphincter ductus pancreatici, musculus sphincter pupillae, musculus sphincter pylori, musculus sphincter urethrae, musculus sphincter vesicae, physiological sphincter, pupillary, pupillary reflex, pyloric sphincter, sphincter, sphincter ani, sphincter muscle, urethral sphincter