szemfehérje

Szemfehérje, also known by its scientific term sclera, refers to the white, opaque, protective outer layer of the eye. It is a tough, fibrous tissue that covers roughly five-sixths of the eyeball's surface. The sclera's primary functions include maintaining the shape of the eye, protecting its internal structures from injury, and providing attachment points for the extrinsic muscles that control eye movement.

The sclera is composed of dense connective tissue, primarily collagen fibers arranged in a complex, interwoven pattern. This arrangement gives it its strength and rigidity. While predominantly white, the sclera can appear slightly bluish in infants due to the thinner tissue. In older individuals, it may develop yellowish deposits called pingueculae or pterygia, which are benign growths.

Blood vessels are present on the surface of the sclera, particularly in the episclera, a thin layer of tissue covering it. These vessels are responsible for supplying nutrients and oxygen to the outer layers of the eye. Certain medical conditions can cause changes in the sclera's appearance, such as redness due to inflammation (scleritis) or a yellowing tint (jaundice). The posterior part of the sclera is continuous with the dura mater, the outermost membrane surrounding the brain.