Keratoconus is a progressive condition that leads to increased bulging of part of the cornea together with increasing levels of astigmatism and decreasing vision. Most patients with keratoconus find that their vision is better with a rigid contact lens rather than with glasses. Some patients can't tolerate contact lenses or may prefer not to wear them and one alternative is the implantation of a Keraring into the cornea. Kerarings work by changing the shape of the cornea to a more optimal shape.This can result in better un-aided vision and better vision with glasses in up to 2 out of 3 patients. In 1 of 3 patients Kerarings aren't helpful but are fully reversible. Kerarings may be combined with corneal collagen cross-linking or with an implantable contact lens to allow the patient to see without glasses or contact lenses. Kerarings aren't suitable for everyone and you should consult a corneal expert for the best treatment for your eyes.