The cornea is the clear, outermost layer of the eye and is responsible for 2/3 of the focusing power of the eye. . Measuring just 10 x 11 mm and only being 0.5mm thick, the cornea is extremely important. In order to have good vision, the cornea must be clear and evenly shaped. The cornea also functions as a protective barrier against infective agents, for example, bacteria and viruses as well as contaminants like dirt and dust. To learn more about the cornea and corneal conditions, please click on the links below.