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Correct Your Vision While You Sleep – Orthokeratology/CRT

-The Eye Digest-

Correct Your Vision While You Sleep - Orthokeratology/CRT

Contact lenses present a fantastic opportunity to enjoy clear and crisp vision without the need for glasses.   However, contact lenses worn during the day still have their drawbacks. Lenses can dry out, collect deposits, rip, or even fall out!   Although, these misfortunes tend to be few and far between, they still do happen. So how can we get around this? Are there other options for contact lenses, perhaps a contact lens that can be worn at night?

Meet orthokeratology.

Orthokeratology (abbreviated as Ortho-k) or CRT lenses are nighttime contact lenses. They are classified as rigid gas permeable lenses and are a safe and effective method of correcting nearsightedness and astigmatism without the need for daytime contact lenses or ortho k contact lensglasses.


So how does Ortho-k work?

Ortho-K lenses are applied at bedtime and worn overnight. While asleep, the reverse geometry aspect of the rigid gas permeable lens reshapes the cornea (front of the eye). As the cornea is reshaped, refractive error is removed. Thus, after a full night of slumber, the ortho-k user wakes up with perfect to near perfect vision!

ortho k effects1


Who can use Ortho-K lenses?

Orthokeratology is frequently a good option for patients that are too young for LASIK surgery or for patients that are not good candidates for vision correction surgery.10 Because it can be discontinued at any time without permanent change to the eye, people of any age can try the procedure, as long as their eyes are healthy. In fact, we often give Ortho-K the nickname “LASIK in a box.”

Ortho-k can be very useful for individuals who participate in sports, or who work in dusty, dirty environments that can make contact lens wear difficult.   Going about these activities without the need for glasses or contact lenses can drastically improve performance and the subjective experience.


I’ve heard the buzz…can ortho-k really slow down or stop myopia in children?

child and optical glasses 208522Yes!   Research has shown that Ortho-k can slow down or even halt the progression of myopia (nearsightedness) in children and adolescents. We currently have 4 methods that we commonly employ to attempt myopia control, and in our personal clinical experience, ortho-k/CRT is one of our most effective clinical methods of Myopia Control (part of our #StopNearsightedness campaign).


What results can you expect from ortho-k?

The goal for ortho-k is to correct your vision to 20/20 without eyeglasses or contact lenses during the day. In FDA trials of both CRT and VST lenses, more than 65% of patients were able to achieve 20/20 visual acuity after wearing the reshaping lenses overnight. More than 90% were able to see 20/40 or better.   In our office, nearly every Ortho-K patient has achieved 20/20 vision with the lenses.


How long does ortho-k take?

Though you may see some improvement in your vision after a day or two of overnight ortho-k, it can take several weeks for the full effect to be apparent. During this time, your vision will not be as clear as it was with glasses or contacts, and you are likely to notice some glare and halos around lights. It’s possible you may need a temporary pair of eyeglasses for certain tasks, like driving at night, until your vision is fully corrected by the ortho-k lenses.


Is ortho-k comfortable?

Since ortho-k GP lenses are worn during sleep, comfort and lens awareness are generally not a problem.


I am interested in Ortho-K for my child or myself! Who should do my Ortho-K fitting?

When starting Ortho-K it is important to choose an eye care provider that is licensed, certified and has ample experience in the field. Ortho-K fittings are much more complicated than standard soft lens fittings, and thus require a practitioner to be skilled and vigilant.

At our office, both of our doctors have a great amount of experience with a variety of types of Ortho-K cases (as well as licensure and certifications). In fact, each of our doctors has seen over a hundred different Ortho-K cases. If you are interested in Ortho-K, do not hesitate to contact us at (650) 948-3700!


-Dr. Aaron Neufeld

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Dr. Aaron Neufeld is the Chief Optometrist at Los Altos Optometric Group and primary author and editor of The EYE Digest.

Contact him with questions or ideas for future articles at (650) 948-3700 or


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