Keratoconus is a progressive disorder where a section of the cornea thins and bulges forward as a cone. This causes a distortion of the light reaching the retina. People with mild keratoconus may still be able to successfully wear glasses. As the disorder progresses, vision with glasses becomes more distorted and contact lenses help provide the best vision. Scleral contact lenses are recommended because the tears and fluid behind the lenses help to minimize the visual distortion. A patient with keratoconus may be recommended for corneal cross-linking surgery to strengthen the cornea and slow down progression. If keratoconus progresses too far, a corneal transplant may be needed.