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Orthokeratology (CRT & VST)

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Orthokeratology is overnight vision correction using corneal reshaping lenses.

It is also called corneal refractive therapy.

This is a reversible method of treatment for myopia (near-sighted) patients and generally works for prescriptions up to -4.00D if there is not too much astigmatism (less than -1.25D). The treatment involves wearing a rigid gas permeable lens while sleeping. With good success, most patients have very stable vision and find they can miss an occasional overnight cycle without any vision loss after approximately 3 weeks of lens wear.

Sometimes it doesn’t work. Some corneas are too rigid and don’t respond adequately to the moulding design of the lens. Sometimes during sleep, the position of the eye, the tension of the eyelids and the sleep posture can affect the orientation of the lens on the cornea.

For this reason, we monitor the results with a corneal topographer so we can measure more accurately what is happening to the front part of the eye.

Today’s Orthokeratology lenses are based on a specific design that was approved for overnight wear in 2002 and are much more successful than earlier designs. Dr. Ben Giddens is an authorized fitter of Paragon CRT lenses (Paragon Vision Sciences) and Vision Shaping Treatment lenses (Bausch and Lomb).

Talk to our optometrists in Georgetown, Ontario to see whether Ortho-K makes sense for you or click here to learn more about it.



We are pleased to announce that we will be reopening our doors and resuming routine eyecare as of Monday, June 1st. Please click here to read our new protocols.

With everyone’s safety in mind, we have a strict disinfection policy in place and will have a tight control on the number of people allowed in the office at any one time. We encourage you to call or email us to book an appointment for an eye exam or eyewear purchase, in order to prevent any over crowding. We appreciate your understanding and cooperation and look forward to seeing you soon!