Contact Lenses
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Night Lenses (Ortho-K)

Published on
December 4, 2023
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Night Lenses, also known as Orthokeratology lenses or Ortho-K, are rigid contact lenses worn while you sleep, leaving you with clear vision during the day without the need for contact lenses or glasses.

See this page for more information on orthokeratology lens care.

What is Orthokeratology?

Orthokeratology, often abbreviated as Ortho-K, derives its name from "ortho," meaning correction (as in orthopaedics or orthodontics), and "kera," which relates to the cornea—the eye's front surface. Custom-designed Ortho-K contact lenses are worn overnight, gently reshaping the cornea. This innovative process aims to reduce or eliminate various refractive errors, including short-sightedness (myopia), presbyopia, and astigmatism. It's also an effective tool in Myopia Control, halting the progression of short-sightedness.1

4 illustrated cross sections of a cornea undergoing orthokeratology treatment, showing the step by step change as the lens corrects refractive error
Figure 1. Orthokeratology lenses flatten the central cornea, using fluid forces to mould the cornea to match the shape of the lens.

How do Night Lenses work?

Night Lenses (Ortho-K) use the tears underneath the lens to change the corneal shape, either flattening the centre to correct short-sightedness or vice versa for long-sightedness.2 Our optometrists can successfully fit Night Lenses for both children and adults, addressing various refractive errors or glasses prescriptions.

At Innovative Eye Care, we use state-of-the-art technology to capture the three-dimensional surface of the eye. These measurements are exported to a computer program called EyeSpace, which uses a computer simulation of the Night Lens on your eye to create a custom fit. This eliminates the uncomfortable, invasive, trial-and-error process of an archaic diagnostic fitting and ensures the highest level of accuracy for the greatest chance of successful lens fittings, even for complex eyes. Our optometrist, Lachlan Hoy, played a pivotal role in developing EyeSpace, which is now utilized by contact lens practitioners worldwide, including in Australia, the US, New Zealand, and South Africa. EyeSpace tailors each lens to your prescription and eye shape with unparalleled accuracy smaller than one micron (that's 1000 times smaller than one millimetre!).

Figure 2: A gorgeous fitting myopic Night Lens

If you want to find out more about Night Lenses, please book an appointment with us.

Why Night Lenses?

  • Immediate improvement: After one night, about half of the total correction needed has been achieved, and within a week vision has completely stabilised. Higher refractive errors may find this takes between two to four weeks.
  • No daytime wear: Because the reshaping takes place while the lens is worn overnight, no optical aid is needed the next day to see. This is especially helpful for people who play sport, work in dusty or dry environments or those who have dry eyes and allergies. It’s also useful for those who are prone to misplacing or breaking optical aids like glasses and contact lenses.
  • Safe and effective: Night Lenses are completely reversible, unlike surgical procedures like LASIK, and the cornea will return to its normal shape within one to two weeks. Research has also found that Night Lenses have low levels of red eye events like infections, comparable to other kinds of overnight wear soft contact lenses.3,4
  • Perfect for swimming: Most varieties of contact lenses are not best used when swimming or showering due to the risk of eye infection. As Night Lenses are worn whilst sleeping, the need to wear vision corrective lenses when swimming or showering is eliminated.

Two 3d topographical maps of a cornea before and after orthokeratology treatment.
Figure 3. Corneal topographies taken before myopic Night Lenses treatment (left) and after (right). Exaggerated 3D representation. Central area inside the red-ring has been flattened, correcting the short-sightedness.

 Please see down below for frequently asked questions.

Night Lenses (Orthokeratology) for Myopia

Night Lenses are a powerful tool for managing progressive myopia, and the results from our practices in Adelaide and Henley Beach are truly promising. Many of our patients have experienced not only a significant reduction in myopia progression but even complete halting through Night Lenses. Our skilled optometrists are often able to achieve much clearer vision and healthier eyes with Night Lenses.

Understanding Myopia

Myopia (short-sightedness) refers to eyes that see clearly when observing near objects but see poorly looking at distance objects. This condition occurs when the eyeball grows too long compared to the eye's power. Consequently, light rays focus in front of the retina rather than directly on its surface. Myopia often emerges in childhood and can have a genetic link, but environmental factors, such as extensive near work and lack of outdoor time, also play a crucial role. These are not the only risk factors, as many outdoor loving individuals with no family history are still developing myopia.  

Myopia Prevalence:

The prevalence of myopia is on the rise worldwide, with staggering statistics:

  • Approximately 1.4 billion people globally have myopia.
  • This number is projected to reach half the global population by 2050.
  • In Taiwan, 93% of 18-year-old girls suffer from myopia.
  • In Singapore, 7 out of 10 college graduates are myopic.
  • In urban China, up to 78% of 15-year-old girls experience myopia.

Progression and Associated Risks:

Adult-onset myopia (developing after 20 years of age) can progress over time, though youth-onset (before 20 years) generally shows more aggressive progression which continues until the eye stops growing. Typical sufferers are highly dependent on expensive, high-powered glasses or contact lenses and require frequent replacements as the condition escalates.

All levels of myopia increase the chance of these blinding conditions:

  • Retinal detachment
  • Cataracts
  • Glaucoma
  • Myopia retinal degeneration

These risks escalate as the level of myopia increases. Myopia maculopathy, a progressive condition causing holes in the retina due to over-stretching, is the fourth most common cause of visual impairment in the UK ahead of diabetic eye disease.

Studies show the risk factor for eye disease due to myopia is comparable to the risk of cardiovascular disease due to untreated high blood pressure. The risk for glaucoma and cataract due to myopia compares to the risk of stroke from smoking over 20 cigarettes per day. For retinal detachment and myopic maculopathy, myopia carries a risk far greater than any identified population risk factor for cardiovascular disease. Given that higher levels of myopia entail a higher risk of these conditions, halting this progression can broadly prevent a significant level of blindness.

Treatment with Night Lenses:

Standard spectacle lenses or contact lenses do not slow myopia progression. Patients using these methods face ongoing lens updates and future sight-threatening problems. Since the elongation of the eye causing myopia cannot be reversed, early intervention is crucial. The good news is that evidence supports the effectiveness of certain treatments in slowing or halting myopia progression, with Night Lenses being one of the most effective options available.

Research indicates that Night Lenses can slow myopia progression by 32% to 100%, with most studies suggesting around 50%. Our practice and others in Australasia have witnessed complete halting of myopia progression in some patients.

Night lenses work by altering the shape of the eye's surface, allowing central light to focus accurately on the retina and off-centre light to focus in front of the retina. This prevents the retina from attempting to elongate the eye further.

Don't wait to take control of your myopia. Learn more about myopia control in children and how Ortho-K can make a difference.

How many appointments will I need?

What to Expect with Night Lenses:

Initial Appointment: During this appointment we will check suitability for Night Lens wear. At Innovative Eye Care, we have a range of state-of-the-art technology to assist us. This includes slit lamp imaging to determine whether the surface of the eye is healthy, checking your prescription with subjective and objective refraction and therefore determine the amount of correction needed, mapping the cornea with corneal topography and tomography to design the lens, and in the case of myopia control, analysing the length of the eye with ocular biometry to see if Night Lenses are required to slow down growth.  

Delivery and Teach: If you've never worn contact lenses before, don't worry. Our team will guide you through the process step by step. We provide helpful resources on our website for practicing lens insertion and maintenance techniques. During your appointment, we'll ensure the perfect fit and teach you how to insert, remove, and care for your Night lenses. We have plenty of Night Lenses (Orthokeratology) guides on the Innovative Eye Care Patient Resources.

First Morning: On the first morning after Night Lenses, your vision may not be fully corrected yet. Try to remove the lenses immediately upon waking, to relieve sensitive irritated eyes. You might need someone to drive you to your follow-up appointment. Your optometrist will assess your prescription changes and provide disposable soft lenses if needed while your Night lenses continue reshaping your eyes overnight.

One Week: In just one week, most patients will notice clarity of vision will be nearing 100%. Your optometrist will fine-tune your lenses if necessary, ensuring optimal performance and comfort. Any replacements covered under warranty can be ordered.

Ongoing Follow-Ups: Following the one-week appointment, regular follow-ups are crucial. You'll have appointments at one month, three months, six months, and eventually yearly reviews if needed. These appointments are essential for monitoring the success of the Night Lenses procedure and your eye health. The first 6 months of follow-ups are included in the Night Lens program at no extra cost.

For detailed instructions on caring for your Night lenses, visit our Orthokeratology lenses care page.

Getting Started:

A full eye exam at Innovative Eye Care is necessary prior to starting Night Lenses, even if you have had a recent eye examination at another optometrist. Several aspects of your eyes including health, vision and corneal shape will have to be assessed to establish if your eyes are suitable. If in the last 12 months you have had a full eye exam with us, you may just need a corneal topography and a quick discussion with your optometrist to see if Night Lenses are right for you.

If you're curious about the benefits of Night Lenses for your eyes, don't hesitate to book an appointment with us at our Adelaide or Henley Beach practices.


1) Mountford, J., Ruston, D., Dave, T. (2004) “Orthokeratology.” 1st ed. Edinburgh: Butterworth-Heinemann.

2) Hiraoka, T., et al., 2018. Safety and efficacy following 10-years of overnight orthokeratology for myopia control. Ophthalmic Physiol Opt 38(3): 281-289.

3) Bullimore, M. A., et al., 2013. The risk of microbial keratitis with overnight corneal reshaping lenses. Optometry and Vision Science 90(9): 937-944.

4) Efron, N. (2012). “Corneal Warpage.” Contact Lens Complications. 3rd ed. Sydney: Elsevier.

5) Wildsoet, C. et al. (2019). “IMI – Interventions for Controlling Myopia Onset and Progression Report”. Invest Ophthalmol Vis Sci 60(3): M106-M131.

6) Korszen, E. and P. Caroline (2017). “The Anatomy of a Modern Orthokeratology Lens.” Contact Lens Spectrum 32(March): 30-35.

7) Hiraoka, T., et al., 2018. Safety and efficacy following 10-years of overnight orthokeratology for myopia control. Ophthalmic Physiol Opt 38(3): 281-289.

8) Resnikoff S, Jonas JB, Friedman D, et al. Myopia – a 21st century public health issue. Invest Ophthalmol Vis Sci. 2019;60:Mi–Mii.

9) Wolffsohn JS, Flitcroft DI, Gifford KL, et al. IMI – Myopia control reports overview and introduction. Invest Ophthalmol Vis Sci. 2019;60:M1–M19.

10) Daniel Ian Flitcroft, Mingguang He, Jost B. Jonas, Monica Jong, Kovin Naidoo, Kyoko Ohno-Matsui, Jugnoo Rahi, Serge Resnikoff, Susan Vitale, Lawrence Yannuzzi; IMI – Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest. Ophthalmol. Vis. Sci. 2019;60(3):M20-M30. doi:10.1167/iovs.18-25957.

11) Christine F. Wildsoet, Audrey Chia, Pauline Cho, Jeremy A. Guggenheim, Jan Roelof Polling, Scott Read, Padmaja Sankaridurg, Seang-Mei Saw, Klaus Trier, Jeffrey J. Walline, Pei-Chang Wu, James S. Wolffsohn; IMI – Interventions for Controlling Myopia Onset and Progression Report. Invest. Ophthalmol. Vis. Sci. 2019;60(3):M106-M131. doi:10.1167/iovs.18-25958.  


Please browse through some of our most frequently asked questions on this topic.

Can children wear Night Lenses?
There is no age limit for night lenses; children as young as six have been successfully and safely fitted with the lenses to reduce or halt the progression of short-sightedness. It is one of the most common methods of vision correction for patients under 18 in our practice. Likewise, adults as old as eighty have successfully worn Night Lenses to provide visual correction.
Can Night Lenses damage my eyes?
The treatment itself is completely reversible and the cornea will return to its shape prior to wearing night lenses after they are no longer worn for a period of time. As with any contact lenses, there is the potential for inflammation or infection, but research shows that in Night Lenses this is less than half as frequent as when wearing other overnight lenses. This is because night lenses are made from a material that allows much more oxygen to reach the cornea, which maintains its overall health. Careful hygiene, correct lens care regimes and replacement of the lenses every 1-2 years reduces the risk of any complications.
How new are Night Lenses (orthoK)?
The idea of corneal moulding to correct myopia may have originated millenia ago when the Chinese placed bags of sand over their eyelids to improve vision. Orthokeratology as we know it today has been around since the 1940s and has been continuously refined over the decades to a point where it is now produces reliably safe and predictable correction.
How often will I need to wear my Night Lenses?
This depends on the individual. For most patients, wearing the lenses every night ensures clear vision during the day, but as the correction stabilises some people find they only need to wear the lenses every second night. Because the cornea slowly starts to return to its normal shape after the lenses are removed, the vision will become blurrier the more nights that are missed. However, wearing every night is not essential, and a back-up pair of spectacles or soft contact lenses can be worn during the day if this is a regular occurrence.
How do I get started with Night Lenses?
A full eye exam at Innovative Eye Care is necessary, even if you have had a recent eye examination at another optometrist. Several aspects of your eyes including health, vision and corneal shape will have to be assessed to establish if your eyes are suitable. If in the last 12 months you have had a full eye exam with us, you may just need a corneal topography and a quick discussion with your optometrist to see if Night Lenses are right for you.

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