Ortho-K is a non-surgical process which reshapes (flattens) the cornea of the eye using contact lenses. Accelerated Ortho-K uses reverse geometry contact lenses. Flattening the cornea reduces the focusing power of the eye.
If the amount of corneal flattening is accurately controlled, it is possible to bring the eye into correct focus and compensate for myopia (nearsightedness). After the contact lens is removed, the cornea retains its flattened shape for part or all of the remainder of the day. A retainer lens must be used each day to maintain the corneal flattening, or the myopia will revert to the pre-treatment level.