Corneal reshaping or refractive lenses are rigid gas permeable contacts that are custom-fitted by an eye care professional. They are worn overnight, and are intended to reshape the cornea to correct minor degrees of nearsightedness and astigmatism in adults. These lenses do not correct vision while they are worn. Instead, vision is corrected for several hours after wear, because the cornea has been temporarily reshaped during sleep. The procedure is called orthokeratology, and the results are variable. This type of contact lens should be fitted only by an eye care professional with specialized training