Keratoconus is an eye condition where the cornea thins and causes a distortion to its surface. 90% of the cornea is made from overlaid collagen fibrils that are interconnected with cross links to give the cornea strength and stability. When the cornea distorts in shape, patients complain of poor vision - notably, night time haloes and streaks. There are a number of options to improve vision, but none of them stop the disease from progressing. In some patients this means there is a need for a corneal transplant. The results are variable and patients still need to wear glasses or contact lenses. Furthermore, complete healing can take more than a year. In order to maintain the health of the graft, long term eye drops are also required. In order to reduce the likelihood of corneal transplant surgery, it's advisable to consider Corneal Cross Linking treatment. Cross Linking treatment aims to prevent the progression of keratoconus. However, it will not reverse the distortion. Once the eye is numbed with drops, further drops of Riboflavin are added to the eye. Riboflavin is instilled until the cornea is saturated. A small dose of UV-A light is used to activate the Riboflavin. This increases the number of cross links, resulting in a strengthened cornea. Cross linking is the sensible option for patients with mild to moderate, progressive keratoconus.