The term 'EYEBALL' is composed of two parts: the sclera and the outer layer of the. The sclera is the 6-letter word that is used to describe the outer layer of the EYEBALL. It is a tough, white, fibrous membrane that covers the entire EYEBALL and helps to protect it from damage. The sclera also helps to maintain the shape of the EYEBALL and provides a surface for the muscles that control eye movement. The outer layer of the EYEBALL is composed of several layers of tissue, including the conjunctiva, cornea, and choroid. These layers help to provide protection and nourishment to the delicate structures of the eye.