CRT (Orthokeratology, Ortho-K) is a unique type of contact lens designed to temporarily correct myopia (aka nearsightedness or shortsightedness) by gentle, safe and reversible reshaping of your cornea while you sleep. The treatment is designed to enable you to see clearly throughout the day without contact lenses or glasses.

This lens is intended for people with low to moderate myopia (prescriptions up to -6 diopters) and moderate astigmatism.

Your lenses are supplied with a contact lens cleaner for daily use. Our optometrists will instruct you about what care system is best for you and how often your lenses will need to be replaced.

Most patients have rapid improvement in the first few days of treatment and have achieved nearly their optimum vision in 10 to 14 days. A small percentage of patients will not improve enough to function under all conditions without additional correction.

No, it is temporary. If you stop wearing the lenses regularly while you sleep your lens-free vision will return to its original state in as little as 72 hours.

Yes.  There is an increasing amount of data to suggest that CRT reduces the the worsening of myopia.  This may be especially useful in children and young adults.

Yes. If your contact lenses dry out during the day or irritate your eyes, CRT may be an alternative.  Many patients who have dry eye from contact lenses, do not experience symptoms when the lenses are removed. Equally the presence of lenses in the eyes overnight, in some cases may actually be protective against some forms of dry eye.

There is a small risk involved when any contact lens is worn.  Because this procedure is reversible some patients may notice changes in their vision late in the day.  The two most common side effects that occur in rigid contact lens wearers are corneal swelling and corneal surface irritation (both which are reversible). Contact lens can also cause pain, redness, tearing, irritation, discharge, abrasion of the eye or distortion of vision. However the risks are no greater than with any contact lens and less than with most.  Side effects are actually very unlikely and usually temporary if the corrective lenses are removed promptly.  OrthoK lenses are extremely safe.  Please talk to our optometrists for more information about this.

It is important to understand that for a time after you have begun treatment your old glasses will no longer be the appropriate prescription.  Our optometrists will discuss what your options are for visual correction during that time.

It is essential that you discuss any issues you may have about your eye health or contact lens wear with us. If you need any further information about Ortho-K lenses, please contact us