Orthokeratology, also known as ortho-k, is a method used to correct myopia (nearsightedness) or astigmatism by wearing rigid gas permeable contact lenses overnight, so that no corrective lenses are needed during daytime hours.
Gas permeable (GP) lenses specialized for ortho-k are inserted at bedtime and worn as you sleep. The lenses reshape your cornea gently giving you a temporary vision correction for the next day. In order to maintain sharp visual acuity on a daily basis, you need to wear the ortho-k reshaping lenses every night.
Ask your eye doctor at your next exam if you are a good candidate for Ortho-K; and he/she will discuss options with you.