The term 'PUPIL's Surrounder' is a reference to the IRIS, which is the colored part of the eye that surrounds the PUPIL. The IRIS is responsible for controlling the amount of light that enters the eye and helps to focus the light on the retina. It is made up of two layers of smooth muscle fibers that contract and expand to adjust the size of the PUPIL. The color of the IRIS is determined by the amount of melanin present in the tissue.