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What Are Ortho-K Lenses?

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A woman holds onto an ortho-k lens between her index finger and her thumb

Many individuals would appreciate being able to experience daily living without using their glasses or contacts. While permanent forms of vision correction are available, not everyone is interested in undergoing eye surgery. Ortho-k lenses provide a unique alternative! 

Orthokeratology (ortho-k) lenses are worn while sleeping to temporarily reshape the cornea. This provides temporary vision correction and reduces the need to use glasses or contacts during the day. 

Ortho-k lens treatment for vision correction does not require surgery, lasers, or drugs, and treatment can be stopped at any time! Ortho-k is a collaborative eye treatment that requires individuals to check in with their optometrist to help make sure everything is running smoothly. 


Orthokeratology (ortho-k) lenses are specially designed gas-permeable contact lenses worn overnight while sleeping. These lenses gently reshape the curvature of the eye’s cornea to help improve vision during waking hours. 

This results in a non-invasive form of vision correction that reduces the need to wear glasses or contacts during waking hours. For most individuals, vision correction from ortho-k lenses may last most of the day, while others may notice their vision correction slowly wear off towards the end of their day.

Vision correction results from ortho-k lenses are not instantaneous. Patients with a light prescription may notice clear vision after a few days, and those with higher prescriptions may notice clear vision after a few weeks of consistent wear. 

For best results, it’s important to wear ortho-k lenses every night and follow the directions from your optometrist.   

How Do Ortho-K Lenses Work? 

Ortho-k lenses help correct vision by temporarily reshaping the cornea. The cornea is a clear, round structure that covers the pupil and iris at the front of each eye. It helps the eye focus. It bends light as it enters the eye and focuses light onto the retina, which helps us see. 

These specialized lenses are worn while sleeping, keeping the eye moisturized because oxygen can permeate the lens. This lens technology makes ortho-k a potential solution for individuals experiencing dry eyes

During sleep, ortho-k lenses flatten the cornea’s center by applying mild pressure, correcting refractive errors by altering how light enters the eye. Upon removal in the morning, the cornea remains reshaped and can provide clear vision throughout the day.

Vision correction with ortho-k is stable, not permanent. If ortho-k lenses aren’t regularly worn overnight, the cornea can begin to lose its adjusted shape, and the initial refractive error will return.

The importance of consistently wearing your ortho-k lenses to maintain clear, corrected vision can be compared to dental retainers. Not wearing your retainer for a few nights can result in your teeth slowly shifting back to their position before braces. Similarly, not wearing your ortho-k lenses for a few nights can cause your eyes to revert to their original shape, and the refractive error will return. 

To maintain vision correction with ortho-k, wear your lenses every night.

Who Can Benefit From Wearing Ortho-K Lenses? 

Ortho-k is mainly used to correct myopia. Individuals with refractive errors like hyperopia and astigmatism may also benefit from vision correction with ortho-k lenses.

Many individuals can benefit from ortho-k lenses, such as:

Like LASIK and PRK corrective surgery, not everyone is a good candidate for ortho-k lenses. Corneal curvature and prescription strength influence a patient’s candidacy. Ortho-k lenses work best for patients with up to -6.00D of myopia and less than -1.75D of astigmatism

The first step is a comprehensive eye exam to determine if you are a suitable candidate. If ortho-k is an option, your optometrist will measure your corneal shape and map out your personalized lens prescription.

Ortho-k lenses are not recommended for individuals with eye diseases or ocular concerns like:

  • Glaucoma 
  • Cataracts 
  • Keratoconus 
  • Large pupils  
A woman holds onto a contact lens case and an ortho-k lens

Are Ortho-K Lenses Safe?

Safety is a key concern for any vision correction method. Ortho-k lenses are safe when used as directed under the supervision of an eye care professional. The lenses are FDA-approved and designed to allow oxygen to reach the cornea during wear, minimizing the risk of hypoxia or corneal problems associated with other contact lenses.

Like any medical device, ortho-k lenses aren’t entirely without risk. The risks associated with ortho-k lenses are similar to those associated with poor soft contact lens wear and use management. 

Proper lens care and hygiene are fundamental to the safe use of ortho-k lenses.  It’s important to wash your hands before handling the lenses, use the recommended cleaning solutions, and adhere to the prescribed wear schedule. Failure to follow these best practices can increase the risk of microbial keratitis or other infections.

While the overall incidence is low, some users of ortho-k lenses may experience side effects, particularly during the adjustment period. Common issues include:

These symptoms typically lessen as your eyes adapt to the lenses. If any of these symptoms persist, be sure to consult with your optometrist. 

Overall, since corneal reshaping with ortho-k lenses is temporary, little risk is involved. Patients can discontinue wearing their ortho-k lenses anytime and resume wearing their glasses or contacts. 

Schedule a Consult in London, ON 

Ortho-k lenses can provide non-invasive temporary vision correction. They are a great option for patients with active lifestyles, dry eyes, children requiring myopia management, and those not interested in permanent corrective eye surgery.

Unfortunately, not every patient is a great candidate for ortho-k treatment. A comprehensive eye exam, consultation, and fitting with your optometrist can help determine if ortho-k lenses are compatible!  Contact our team at Old South Optometry to schedule your ortho-k lens consult.

Written by Old South Optometry

We consider ourselves a true family eye care centre in the heart of London, Ontario. We are lucky enough to have helped whole generations—working with children, parents, and grandparents, all of the same family. Visit Old South Optometry today to make an eye care appointment!
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