Keratoconus (KC) is a disorder of the eye which results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, astigmatism, and light sensitivity. Symptoms are blurred or distorted vision, increased sensitivity to bright light and glare, frequent changes in eyeglass prescriptions, worsening or clouding of vision. Causes of keratoconus can be genetic and environmental factors. Keratoconus is treated by ophthalmologists.