Orthokeratology is known variously as corneal molding, corneal reshaping therapy, vision shaping therapy and other monikers. In orthokeratology, typically a myopic eye is fitted with an rigid gas permeable lens that is very flat centrally, but has a reverse curve (steeper than the base curve) in the mid periphery. The lens then flattens and rearranges the corneal epithelium such that the shape of the anterior cornea changes from prolate to oblate. This results in a temporary reduction or elimination of myopic refraction. Users must wear the lenses for about eight hours at least every 2-3 nights to maintain the shape. The fit seen here is ideal: there is slight pooling in the area outside of the visual axis compared to the center and there is seal off adjacent to the periphery.
Ophthalmic Atlas Images by EyeRounds.org, The University of Iowa are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.