The sclera is the part of the eye commonly known as the"white". It forms the supporting wall of the eyeball, and is continuous with the clear cornea. It is covered by the conjunctiva, a clear mucus membrane that helps lubricate the eye. It is thickest in the area surrounding the optic nerve. It is made up of three divisions: the episclera, loose connective tissue, immediately beneath the conjunctiva; sclera proper, the dense white tissue that give the area its color; and the lumina fusca, the innermost zone made up of elastic fibers. There are a number of abnormalities associated with the sclera. Some are genetic and include: Melanosis: excess deposits of melanin on the surface of the scleara, which can become inflamed and uncomfortable Coloboma: notching and bulging of the sclera as lesions Ectasia: a thinning and bulging of the sclera Treatment for these is either unavailable or impractical. Acquired abnormalities of the sclera include: Ectasia that can be brought on as a side effect of traumas, or inflammations Episcleritis: a hypersensitivity reaction which can be anterior or posterior, and is characterized by engorged blood vessels, and can also affect the cornea