Iris sphincter muscle Iris sphincter muscle The iris sphincter muscle (pupillary sphincter, pupillary constrictor, circular muscle of iris, circular fibers) is a muscle in the part of the eye called the iris. It encircles the pupil of the iris, appropriate to its function as a constrictor of the pupil. It is found in vertebrates and some cephalopods. Initially, all the myocytes are of the smooth muscle type but, later in life, most cells are of the striated muscle type. Its dimensions are about 0.75 mm wide by 0.15 mm thick. In humans, it functions to constrict the pupil in bright light (pupillary light
The Light That Failed (1939 film) learn the truth at some point, she then confesses what she has done. Once the news sinks in, he changes his plans. Dick travels back to the Sudan, where he puts on his old uniform and hires a guide to take him to join Torp. They ride in on horseback in the midst of a battle. Sensing that the British cavalry is about to deploy, Dick gets Torp to direct him into the midst of the charge, where he is shot and killed by a native. The Light That Failed (1939 film) The Light That Failed is a 1939 drama