a scleral lens is provided with a drug that is retained in the reservoir of fluid between the scleral lens and the cornea . this system can be used to deliver drugs not currently used because of poor bioavailability , to increase bioavailability of drugs used in patients already wearing a scleral lens , and to improve bioavailability in patients who are not currently wearing the lens . dosing can be provided less frequently , thus decreasing the risk of non - compliance .