Keratoconus is a progressive disease where an area on the cornea becomes thinner and bulges forward in a cone shape. In the very earliest stage, keratoconus causes the eye to become more nearsighted, but the vision may be normal with glasses. As the disease progress, the vision cannot be entirely corrected with glasses and the patient notices blurring and distortion of vision and increased sensitivity to glare and light. Rigid contact lenses are the primary method of treatment for mild to moderate cases. Advanced cases, characterized by severe steepening of the cornea and/or corneal scarring, are treated with corneal transplantation. A newer technology called Intacs may offer a less invasive option for the treatment of keratoconus in all except the most advanced cases.

Eyes with even the earliest stages of keratoconus should not have LASIK surgery. These eyes are usually better treated with Intacs or other options.

Advanced keratoconus. The cornea appears like a cone instead of the normal spherical shape. A scar forms on the tip of the cone