Sclera refers to the outer white part of the eye, which passes in front of the cornea. It consists of connective tissue, and the outer layer contains collagen and elastic fibers. The sclera protects the inside of the eye and it is clamped with extraocular muscles. The sclera consists of three layers: episclera, scleral stroma, and lamina fusca. In front of the eye, the sclera passes the cornea, and this site is called the limbus. In early childhood, the sclera may be slightly transparent, whereas an adult has a white sclera. In advanced age, the sclera might appear slightly yellow, due to fat deposits.