Overview
Keratoconus is a progressive thinning of the cornea and is the most common cornea dystrophy in the United States, according to the National Eye Institute. In fact, it affects one in every 200 Americans. It happens when the middle of the cornea thins and bulges outward, gradually forming a rounded cone shape. This changes the cornea’s refractive power producing astigmatism, or distortion, and nearsightedness, or blurriness.