Biomechanical modeling of the human eye with a focus on the cornea

The human eyeball is an imperfect globe, with the cornea having a smaller radius of curvature than the remaining portions of the eyeball. The visible white opaque portion of the eyeball is called the sclera. The cornea forms the transparent outer covering of the visible colored portion of the eyeball, the color being due to the underlying iris. The interface between air and the cornea forms most of the optical power of the eye. The curvature of the cornea is responsible for roughly two-thirds of the refraction of light in the eye and the slightest imperfection in its shape results in astigmatism and refractive error. The corneal thickness in the central region is 0.52 mm with a standard deviation of 0.04 mm. The cornea thickens toward its periphery, where its value is about 0.65 mm (Figure 10.1) (Pinsky and Dayte, 1991).