Orthokeratology (ortho-K) is a non-surgical vision correction technique in which specially designed rigid gas permeable contact lenses are worn overnight to temporarily reshape the cornea. Upon waking, the lenses are removed, and the cornea retains a modified shape that corrects short-sightedness (myopia) throughout the day without the need for glasses or daytime contact lenses. Beyond providing convenient daytime vision, ortho-K has become one of the most effective and widely studied methods for slowing the progression of childhood myopia.

How Ortho-K Slows Myopia Progression

Myopia develops when the eye grows too long, causing light to focus in front of the retina. Research suggests that peripheral retinal defocus plays a major role in signalling the eye to elongate. Ortho-K reshapes the cornea so that while central vision is clear, the peripheral retina receives slightly myopic (focused in front of the retina) defocus. This altered optical profile reduces the stimulus for eye elongation. Numerous studies have demonstrated that ortho-K can slow axial elongation—the key factor driving myopia—by approximately 40–60%, making it one of the most effective myopia-control treatments available.

Evidence for Effectiveness

Multiple landmark studies—including the SMART Study (1), LORIC, CRAYON (2), and ROMIO (3) trials—have shown that children wearing ortho-K lenses experience significantly slower myopia progression compared with children wearing glasses or regular soft lenses. These studies consistently report reduced axial elongation, demonstrating that ortho-K provides measurable, long-term myopia-control benefits.

Ideal Age to Start Ortho-K

Children can typically begin wearing ortho-K lenses from about 7 years of age, sometime younger, provided they are motivated and capable of following hygiene and handling instructions. Many practitioners recommend starting as soon as myopia appears—since early intervention leads to better long-term outcomes.

With proper fitting, ongoing monitoring, and high-quality lens care, ortho-K offers children and teens both clear daytime vision and powerful protection against progressive myopia.

Can adults wear ortho-K?

Yes. Ortho-K is generally not required for myopia control in adults since the eye often stops growing in our 20’s, yet adults will still benefit from the benefit of not having to wear glasses or soft contact lenses during day time hours.

Davis, Robert. (2015). Stabilizing Myopia by Accelerating Reshaping Technique (SMART)-Study Three Year Outcomes and Overview. Advances in Ophthalmology & Visual System. 2. 10.15406/aovs.2015.02.00046.
Cho, Pauline et al. “The Longitudinal Orthokeratology Research in Children (LORIC) in Hong Kong: A Pilot Study on Refractive Changes and Myopic Control.” Current Eye Research 30 (2005): 71 - 80.
Cho P, Cheung SW. Retardation of myopia in Orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci. 2012 Oct 11;53(11):7077-85. doi: 10.1167/iovs.12-10565. PMID: 22969068.