IRIS Iris is a dark muscular diaphragm that controls the size of pupil PUPIL A small opening in the iris is known as a pupil. Eye color is specified by that of the iris. Its size is controlled by the help of iris. Function of the Iris: The Breakdown. Structure. The lens is transparent, and can be replaced if necessary. The circular muscles are arranged in concentric rings around the pupil, while the radial muscles run radially. Iris automatically adjusts the size of Pupil according to the intensity of light.Hence, the iris controls the amount of light entering the eye by adjusting the size of pupil.ExampleIf light is bright, it reduces the size of Pupil,so that less light can enter the eyesIf light is dim, it increases the When the circular muscles contract, the size of the pupil decreases and when the radially arranged muscles contract the size of the pupil increases. The iris surrounds a small aperture called the pupil. Lens Focuses light rays onto the retina. The iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. Sphincter pupillae muscle (Musculus sphincter pupillae) Iris is a part of the eyeball that serves the regulation of the amount of light that reaches the retina, as it features an opening called the pupil through which the light can pass through. It controls the amount of light that enters the eye. The iris of the eye is the part of the eye that is located in between the cornea and lens. The iris automatically adjusts the size of the pupil accordingly to the intensity of light received by the eye. The iris controls the size of the pupil and therefore only lets a certain amount of light to enter the eye; The iris contains two sets of smooth muscles- circular muscles and radial muscles. However, the iris is just a muscle controlling the size of the pupil so that the iris can limit the amount of the light entering our eyes. It resides at the bottom part of the pupil right underneath it. And when there is low light, the iris opens up the pupil to let in more light. The iris contains two sets of muscles. The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells.. The iris controls the amount of light entering the eyes. In optical terms, the pupil is the eyeâs aperture, while the iris is the diaphragm. Iris The colored part of the eye which helps regulate the amount of light entering the eye. The iris is a flat and ring-shaped membrane behind the cornea of the eye with an adjustable circular opening in the center called a pupil. Iris Function: Eye Color Definition Unbound in its middle to allow the pupil to change size, this structure is connected to the ciliary bodyâthe part of the eye that produces the eyeâs fluid (aqueous humor) and regulates contraction and constriction of the iris. AQUEOUS HUMOR The aqueous humour plays an essential role in the health of your eye. In context|anatomy|lang=en terms the difference between pupil and iris is that pupil is (anatomy) the hole in the middle of the iris of the eye, through which light passes to be focused on the retina while iris is (anatomy) the contractile membrane perforated by the pupil, which adjusts to control the amount of light reaching the retina, and which forms the colored portion of the eye (). Anatomy . The iris is a circular, colored structure that sits in front of the lens within the coronal plane towards the front of the eye. If the amount of light received by the eye is large (as during the day time), then the iris contracts the pupil (makes the pupil small) and reduces the amount of light entering the eye. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae) which pull the iris radially to enlarge the pupil, pulling it in folds. When there is bright light, the iris closes the pupil to let in less light. It is shaped like a small disc and contains fibers & tissues that connect together. The pupil has the function of allowing the light outside to enter the eye.