Keratoconus is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than the more normal, gradual curve that most eyes contain.
Keratoconus can cause substantial distortion of vision and sensitivity to light. It is typically diagnosed in a patient's adolescent years. If afflicting both eyes, the deterioration in vision can affect a patient's ability to drive a car or read normal print.
However, specialty contact lenses can be fitted and are effective enough to allow patients to continue to drive legally and function normally. Further progression of the disease may require surgery for which several options are available, including intrastromal corneal ring segments, corneal collagen cross-linking (currently not FDA approved but clinical trials are being conducted), and, in some advanced cases, corneal transplantation.