The cornea is the dome shaped, clear surface which covers the front of the eye. It is located within the eye’s outer most layer. There are many different kinds of corneal disease, including the coreneal distrophies map-dot-fingerprint, lattice, and Fuchs’ dystrophy. Other corneal diseases include keratoconus and ocular herpes. Diseases of the cornea are some of the most common types of eye problems. There are many functions of the cornea. As the outermost layer of the eye, it can filter some of the most dangerous ultraviolet wavelengths of sunlight to prevent eye injury. Additionally, the cornea focuses and controls the entry of light into the eye by bending or refracting light rays to fall directly on the retina. It also functions as a protection mechanism by helping to shield the entire eye from harmful materials, such as germs. Five basic layers make up the cornea; they are: (i) Epithelium: The epithelium is the cornea’s outermost region, comprising about 10 percent of the tissue’s thickness. (ii) Bowman’s layer: Lying directly below the basement membrane of the epithelium is a transparent sheet of tissue known as Bowman’s layer. (iii) Stroma: Beneath Bowman’s layer is the stroma, which comprises about 90 percent of the cornea’s thickness. (iv) Descemet’s membrane: Under the stroma is Descemet’s membrane, a thin but strong sheet of tissue that serves as a protective barrier against infection and injuries. (v) Endothelium: The endothelium is the extremely thin, innermost layer of the cornea. Endothelial cells are essential in keeping the cornea clear.