Eyelash Circle

**Ciliary circle** The ciliary (ciliary) circle is a semicircular depression on the border between the anterior and middle layers of the eye. The main function of the ciliary circle is to focus light rays using the cornea, which is the refractive surface of both eyes. Also, the ciliary cylinder is involved in the process of accommodation of the lens: contraction of the ciliary muscle leads to the fact that the ciliary cylindrical sac becomes deeper, the curvature of its surfaces decreases, and, consequently, the focal length decreases. Normal functioning of the ciliary muscles is an important condition for the possibility of clear vision at any distance from an object.

The ciliary cylinder of the eye is a half-tube of elastic tissue (ciliard), which closes at the apex with the anterior surface of the iris in the form of a disc—the cilio-corpus. And from below it is closed by a ciliary plate - a root, which fuses with the iris through the pupil.

From the inner surface of the oculomotor muscle at the ciliocorpus it extends into the sac-like ciliary sac. Its length is approximately 9-11 mm, and the width of the ciliary body is 5-6 mm. The surface of the sac is covered with stratified columnar epithelium,

The ciliary circle (orbicula ciliary) is an anatomical formation that is a small round and elliptical smooth muscle layer lining the surface of the iris. The ciliary membrane is located in the central part of the iris, above the funnel and on its posterior edge. The orbital membrane also contains blood vessels that supply the eye and nerve endings that transmit signals to the brain.

Cilia are thin elongated cells that are located in the ciliary body, which gives a rainbow tint to human vision. A special feature of the structure of cilia is their continuous movement. This movement, which plays an important role in the functioning of the eye, involves not only the cells of the membrane, but also the fibers and lens of the eye, which serve as a frame for the ciliary body. In the bright light of the apexterum, the movement of the ciliary cells is inhibited due to the expansion of the muscles. However, in low light, the movements of these cells are already free. In addition to the function of correct focusing vision, ciliary cells are also responsible for the amount of light entering the eye. The pupillary reflex is a mechanism that is associated with the contraction or dilation of the pupils, which are responsible for regulating the light flux, and is nothing more than a reflex. The principle of its operation is that light entering through the pupil triggers a specific process in the retina of the eye, which determines the amount of light transmitted. In addition, the length of this retina directly depends on the distance between a person and the object he is looking at. Therefore, if there is a large distance, most likely, a person’s eyes will not focus to one focal length, since the perception of things occurs due to the clarity and brightness of the light flux. The work of the ciliary circle allows you to regulate the “true” size of the pupil, which is regulated by special muscles and nerves.