Keratoconus is a deterioration of the structure of the cornea with gradual bulging from the normal round shape to a cone shape.
This condition causes decreased visual acuity. The earliest symptom is subtle blurring of vision that cannot be corrected with glasses. (vision can generally be corrected to 20/20 with gas-permeable contact lenses).
The cause is unknown. Keratoconus is more common in contact lens wearers and people with nearsighted eyes.
Contact lens are the primary treatment and are satisfactory treatment for most patients with keratoconus. Severe cases may require corneal transplantation.