What is a cornea?

The cornea is the front clear part of the eye that covers the iris, pupil and anterior chamber. Together with the lens, the cornea refracts light, accounting for approximately two-thirds of the eye’s total optical power. It imparts the greatest focusing power of all the ocular media. The cornea is composed of five distinguishable layers: epithelium, Bowman’s membrane, the stroma, Descemet’s membrane and the endothelium.