Keratoconus is a non-inflammatory ectatic thinning disorder of the cornea that results in poor vision because of irregular astigmatism. In the early stages, eyeglasses and soft contact lenses work. However, in more advanced stages, rigid gas permeable lenses are necessary for improving vision. Because there’s an area of your cornea that is steeper, a poorly fit lens can produce central touch, as in this photo. The lens will be too uncomfortable to wear.