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Orthokeratology, commonly called 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. Throughout the night, the lenses reshape your cornea gently so that your vision becomes clear on the following morning. The correction is temporary, and ideally no eyeglasses or contact lenses will be needed on the next day or two. In order to maintain sharp visual acuity on a daily basis, you need to wear the ortho-k reshaping lenses every night.

At present, three brands of orthokeratology contact lenses are approved for use by the FDA. Euclid Emerald, usually prescribed for myopia control, Paragon Vision Sciences, who produces “Corneal Refractive Therapy” (CRT), and Bausch and Lomb, who manufactures “Vision Shaping Treatment” (VST).

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Q1: What is orthokeratology with CRT Contact Lenses?

Ortho k is a type of nearsightedness, non-surgical control for kids where a hard lens is worn overnight to change the shape of the cornea. The corneal reshaping will reduce the myopia and allow for daytime freedom from any glasses and contacts.

 Q2: Is orthokeratology with CRT Contact Lenses permanent?

No, if you stop wearing the lenses regularly while you sleep, your vision will return to its original state in as little as 72 hours.

Q3: How long does it take for vision correction?

Most patients have accelerated improvement in the first few days of treatment and achieve nearly their optimum vision in 10 to 14 days.

Q4: What should I expect during the 7 to 14 day treatment process?

It’s important to understand that during the short treatment process, old glasses or daytime contacts will no longer be the appropriate prescription. You may need soft contact lenses in the interim.

Q5: Are there any risks involved with wearing CRT Contact Lenses?

When any contact lens is worn, there is a small risk involved. Similarly, it is not expected that the Ortho-K Contact Lenses will provide a risk that is greater than other contact lenses that are worn while sleeping.

Q6: Can I see with my CRT Contact Lenses in night?

Absolutely! If you wake up in the middle of the night, you should be able to see.

Q7: How often will I have to replace my Paragon CRT Contact Lenses?

Generally, the lenses will have to be replaced once a year.

Q8: Are there any age restrictions for orthokeratology?

The CRT Contact Lenses works great for children >6 and teens that are involved in extra-curricular activities. Adults may also enjoy the freedom of Ortho K, especially if they are not a good candidate for Lasik, but still want to explore daytime freedom from glasses or contacts.

Q9: What causes nearsightedness?

Normal and Myopic Eye

Nearsightedness, also called Myopia is a condition in which distant objects appear blurry and out of focus. The cause of nearsightedness can be both genetic and environmental. Less time outdoors and close up work for extended hours (reading, phone or computer usage for example) may increase the chances of nearsightedness which causes the eye to lengthen, preventing light rays from properly focus on the back of the retina resulting in blurred distance vision.

Patient Resources

Application, Removal and Care of Your Paragon CRT Contact Lenses

Eyecare and Esthetics – Same Day/Next Day Appointments