The intrastromal corneal ring segment (ICRS) is a new, implantable device for correcting mild to moderate myopia. ICRS promises several potential advantages, including reversibility, adjustability, and sparing the central cornea, all of which make the ICRSS a promising candidate for addition to the surgical armamentarium of the refractive surgeon. ICRS seem to provide a viable method for treating clear corneal keratoconus for patients who are contact lens intolerant.The corneal steepening and astigmatism associated with keratoconus were reduced, and visual acuity was improved with treatment in almost all eyes. Complications of ICRS including intrastromal tunnel haze, focal white deposits near the ring, perforation of the anterior corneal layer and the posterior one, explantation of the ICRS.Consistent intraocular pressure measurements on eyes with the ICRS.