The eye is a complex and unique part of the human organs that has been considered the window to the human soul. Broadly, the human eye is divided into two segments: anterior and posterior segments. The specific disease conditions of the eye are associated with each of these broad segments. The anterior segment involves the conjunctiva, ciliary body, iris, pupil, anterior chamber, cornea, and lens; the posterior segment consists of the sclera, choroid, retina, macula, and optic nerve.