OK Lens Fitting: How It Works

What if you could correct your vision overnight, simply by wearing lenses while you sleep? You might think that sounds too good to be true, but orthokeratology is a scientifically proven method that gently reshapes your cornea while you sleep.

OK lenses (a.k.a. Ortho-K lenses) do their magic by moulding the front part of your eye to fix refraction errors. Think of it as similar to the way that dental braces work on teeth. We’re gently coaxing the cornea into the right shape for perfect vision. But every patient has corneal surface as unique as their own fingerprint. So in order to prescribe lenses that work for YOU, we need to go through a special fitting process.

But before we get into the nitty-gritty, let me introduce myself. I’m Dr Nick Papadopolous. Proud owner and principal optometrist at Optometrist Parramatta. At our practice we’ve been consistently delivering high quality eye care to the residents of Western Sydney for several decades.

My team and I have a special interest in orthokeratology, so in this article I’m going to share with your the entire journey of getting fitted for OK lenses.


Who Can Wear OK Lenses?

Who benefits from OK Lenses? These lenses offer particular appeal to certain categories of patients.

  • Children: OK Lenses can slow the progression of myopia in children, potentially offering significant long-term benefits for their eye health. This can lead to reduced risk of complications associated with high myopia in adulthood.

  • Adults: For adults, OK Lenses provide an effective way to enjoy perfect vision without the need for daytime glasses or contact lenses. This convenience makes them particularly appealing to those leading busy or active lifestyles.

  • Non-Invasive Alternative: For patients who are hesitant to undergo corrective eye surgery (such as LASIK) or who are not suitable candidates for such options, OK Lenses offer non-invasive vision correction, avoiding any risks associated with surgical procedures.

  • Dry Eye Sufferers: OK Lenses can also be a game-changer for dry eye sufferers. By reducing the need for daytime contact lens wear, they provide much-needed relief from discomfort.

Initial Consultation for OK Lens Fitting

What can you expect during your first visit to our practice for an OK Lens fitting? We start with a discussion about your goals and lifestyle needs. Whether it’s for your child to manage myopia or for yourself to enjoy eyewear-free vision during the day, understanding these details helps us tailor the consultation to suit you best.

Next, we conduct a comprehensive eye examination focusing on the suitability for OK Lenses. This examination includes assessing the shape and health of your eyes. We measure the curvature of your cornea, check for any irregularities, and evaluate how receptive your eyes are to orthokeratology. These insights form the foundation of a successful OK Lens fitting.


After gathering all the necessary information, we discuss the potential benefits and realistic expectations from wearing OK Lenses. You’ll have the opportunity to ask questions and address any concerns you might have. Our aim is to ensure you leave the consultation feeling informed, comfortable, and confident about your decision to try OK Lenses.

ortho k lens fitting process

Eye Measurements and Custom Lens Design

How do we ensure accurate measurements for OK Lenses?

We rely on advanced methods and equipment to obtain precise data, allowing us to design lenses that fit perfectly and reshape the cornea effectively. Here’s a closer look at the key techniques and tools we use:

  • Corneal Topography: This method involves mapping the curvature of the cornea using a sophisticated device known as a corneal topographer. The topographer projects a series of rings or grids onto the cornea, capturing detailed images that reveal its unique shape. This data helps create a contour map of the cornea, which is crucial for designing OK Lenses that fit snugly and provide optimal reshaping.

  • Keratometry: This technique measures the central curvature of the cornea by reflecting light onto its surface. A keratometer, also known as an ophthalmometer, is used to capture the reflection pattern, which is then analyzed to determine the corneal curvature. This information guides the design of the lens, ensuring it reshapes the cornea correctly overnight.

  • Slit-Lamp Examination: We use a slit-lamp microscope to inspect the eye’s anterior segment. By shining a narrow beam of light into the eye, the optometrist can examine the cornea for any abnormalities, scarring, or conditions that may affect the suitability of OK Lenses.

  • Pachymetry: This method measures the thickness of the cornea, providing additional information that helps in designing OK Lenses. A pachymeter gauges the corneal thickness, which is crucial for assessing the eye’s overall health and ensuring the lens design doesn’t cause any complications.

Once we have all the necessary measurements, and you have decided to proceed with OK lenses, we place your order to the orthokeratology lens manufacturer. Some of our lenses are produced in Australia, while others we need to source from overseas. The total time from placing the order until they arrive at our practice is 2-3 weeks.


Learning How to Use OK Lenses

After the lenses arrive at our practice, we’ll invite you to come in for or an initial fitting. Our team of optometrists will guide you through every step, starting with a demonstration of how to insert and remove the lenses correctly, and how to clean and store them. This hands-on guidance helps build your confidence and ensures a smooth experience.

If you want to see what a typical consultation for OK lenses (a.k.a. dream lenses) looks like, watch the following video where 6 year old Ria gets her first pair of orthokeratology contacts.


Regular Checkups and Aftercare

Why are regular checkups essential for OK Lens users?

  • Health Monitoring and Detection of Issues: These appointments help us monitor the health of your eyes and the performance of the lenses. We look for any changes or problems, such as irritation, infection, or other potential complications, making adjustments or recommendations as necessary to maintain eye health.

  • Fit Assessment: During each visit, we assess the fit of the lenses to ensure they continue to reshape your cornea effectively and comfortably. This minimizes discomfort and ensures optimal vision correction.

  • Ongoing Support: These checkups also provide an opportunity to address any concerns or questions you may have, ensuring you feel comfortable and confident in your ongoing use of OK Lenses.

We recommend follow up appointments the next day, and then again after one week, one month, three months and six months, unless otherwise indicated.


Frequently Asked Questions about OK Lenses

Can adults wear OK Lenses?
Yes, OK Lenses are suitable for adults as well as kids. They offer an effective alternative to daytime eyewear, allowing adults and children to enjoy clear vision without needing to wear glasses or contact lenses during the day.

How long does it take for OK Lenses to work?
OK Lenses typically begin to reshape your cornea after the first night of wear. However, it may take several days or weeks of consistent use to achieve stable vision correction.

Can you wear OK Lenses during the day?
OK Lenses are designed to be worn overnight, reshaping the cornea while you sleep. Once you remove them in the morning, your corrected vision should last throughout the day, negating the need to wear the lenses during the day.

Can you read with OK Lenses on?
Yes, you can read with OK Lenses on. While they are designed to reshape your cornea overnight, they don’t impede vision during the night. This allows you to read or watch TV comfortably before bed.

Are OK Lenses and CRT Lenses the same?
OK Lenses and CRT (Corneal Refractive Therapy) Lenses are similar in that both reshape the cornea to correct vision. However, they are made by different manufacturers and may differ slightly in design and materials.

Are OK Lenses and Night Lenses the same?
Yes, OK Lenses are often referred to as Night Lenses because they are worn overnight to reshape the cornea.



The OK Lens fitting process includes a comprehensive eye exam, precise eye measurements, and custom lens design to ensure optimal comfort and effectiveness. Your eyes are unique. And our fitting process reflects that. Think of getting a pair of OK lenses as similar to getting a custom made outfit, rather than a mass produced item off the shelf.

Orthokeratology as a vision correction strategy has many benefits for both adults and minors, while neglecting to explore OK Lenses means you may continue to struggle with eyewear that doesn’t fit your lifestyle or comfort needs.

Embrace a clearer future without glasses or contacts; make an appointment today to find out if OK Lenses are the right solution for you or your child.

To make an appointment, give us a call at 02 9891 2020 or click the “Book Online” button on our website.

Dr Nick Papadopoulos – Owner and Optometrist

B.Optom (UNSW), CertOcTher (ACO) Therapeutically Endorsed Optometrist

Member of the Cornea & Contact Lens Society of Australia & the Orthokeratology Society of Oceania