ABSTRACT
The outer shape of the eye comprises of two spheres of different radii, one set into the other (Figure 11.1). The anterior sphere, the cornea, is the smaller and more curved of the two and is completely transparent. The posterior sphere or sclera is a white, opaque, fibrous shell which encloses the ocular structures. Both tissues are relatively non-distensible and protect the eye from physical damage. The ring where the two areas join is called the limbus.
