Orthokeratology is also sometimes called Ortho-K, CRT (Corneal Refractive Therapy), Corneal Moulding, CCC (Corneal Corrective Contacts), VST (Vision Shaping Treatment), GVSS (Gentle Vision Shaping System), EZM (Eccentricity Zero Moulding) or AOK (Accelerated Orthokeratology).

This procedure has been available for nearly 40 years, however, it is only in the last 10 years that it has become a very feasible option for vision correction. Today, with space-age polymers, computerized corneal scanning, and highly sophisticated, truly accurate computerized lathes, the procedure accomplishes vision correction in a matter of days. In addition, new developments in lens materials have made rigid gas permeable contact lenses more permeable to oxygen enabling safe overnight wear. This allows patients to wear lenses overnight while sleeping and to have good vision throughout the day without using lenses or spectacles.

This procedure is effective in both children and adults, freeing them from spectacles and lenses so that they may enjoy a more physically active lifestyle. Current research shows that there is an added advantage in children as it slows down myopic progression.