Articles

What Is Orthokeratology (Ortho-K)?

Contact Lenses

March 30, 2026

Orthokeratology, commonly known as Ortho-K, is a non-surgical method of vision correction that uses specially designed rigid gas-permeable contact lenses worn while you sleep.

Unlike regular contact lenses, which correct your vision while they are being worn, Ortho-K lenses temporarily reshape the front surface of the eye overnight. This can allow you to see clearly during the day without wearing glasses or daytime contact lenses.

Ortho-K is also used as one of the available optical approaches for myopia control, particularly in children with progressive myopia.

Key Takeaways:

Orthokeratology uses specially designed rigid gas-permeable lenses, rather than regular soft contact lenses.
The lenses are usually worn overnight and temporarily reshape the cornea to improve daytime vision.
The effect is reversible, which means regular lens wear is generally required to maintain the vision correction.
Ortho-K may also be used as part of a myopia-management plan to help slow the progression of childhood myopia.
Proper lens fitting, cleaning and regular follow-up are important because Ortho-K is still a form of contact lens wear.

Orthokeratology (Ortho-K) is a form of temporary vision correction in which specially designed rigid gas-permeable contact lenses are worn overnight to gently reshape the cornea.

The cornea is the clear front surface of the eye and plays an important role in focusing light. For someone with myopia, or short-sightedness, light is focused in front of the retina rather than directly on it, causing distant objects to appear blurred.

By temporarily changing the shape of the cornea, Ortho-K allows light to focus more appropriately on the retina. The lenses are removed when you wake up, allowing you to go through much or all of the day without relying on glasses or regular contact lenses.

The correction is not permanent. If Ortho-K wear is discontinued, the cornea gradually returns towards its original shape and the refractive error returns.

How Does Orthokeratology Work?

Ortho-K lenses are custom-designed according to the shape and refractive characteristics of your eyes.

While you sleep, the lens creates controlled changes across the corneal surface. This alters how light is refracted when it enters the eye and helps provide clearer unaided vision after the lens is removed.

In practice, specially designed Ortho-K night lenses are fitted according to the shape and refractive characteristics of each eye.

The concept may sound similar to LASIK because both change how the cornea focuses light. However, there is an important difference: LASIK permanently alters corneal tissue through surgery, whereas Ortho-K changes the shape of the corneal surface temporarily and does not involve surgery.

For this reason, regular overnight wear is usually required to maintain the effect.

How Does Ortho-K Help Slow Myopia Progression?

Correcting blurred vision and controlling myopia progression are related, but they are not exactly the same goal.

Standard glasses can make distant objects clear, but certain specialised optical treatments are designed to influence how light is focused across both the central and peripheral retina.

Ortho-K changes the optical profile of the cornea after overnight wear. This creates peripheral optical changes that may help reduce the stimulus for further eye elongation, one of the principal structural changes associated with progressing myopia.

The Singapore National Eye Centre (SNEC) lists night-time orthokeratology lenses as one of the available myopia control treatments. SNEC estimates an efficacy of approximately 30% to 50% over three to five years, while noting that individual responses may vary.

This is why Ortho-K may serve two purposes for some patients:

providing clearer daytime vision without glasses; and
forming part of a strategy to slow myopia progression.

Why Is Myopia Progression Important?

Myopia is more than simply needing stronger glasses.

In many people with myopia, progression is associated with an increase in the axial length of the eye. In other words, the eyeball becomes longer as myopia progresses.

Higher levels of myopia are associated with an increased lifetime risk of conditions such as retinal detachment, myopic macular degeneration, glaucoma and cataract, which is why controlling childhood myopia has become an important eye health consideration.

This is particularly relevant in Singapore, where the Ministry of Health has reported myopia prevalence of around 29% among Primary 1 students and 51% among Primary 4 students. The jump across four years of primary school is why the rate of progression matters, not just the prescription at any single point.

The Health Promotion Board’s National Myopia Prevention Programme aims to delay the onset and progression of childhood myopia through annual vision screening, parent education and the promotion of good eye care habits.

Ortho-K should therefore be viewed as one possible part of myopia management rather than as a way to permanently “cure” myopia.

What Are the Benefits of Orthokeratology?

Clearer Vision During the Day Without Glasses

One of the main reasons people choose Ortho-K is the ability to go through the day without wearing glasses or regular contact lenses.

After successful overnight wear, the temporary reshaping of the cornea may provide clear unaided daytime vision.

This can be particularly convenient for people who find spectacles restrictive during daily activities.

May Help Slow Childhood Myopia Progression

Beyond correcting vision, Ortho-K is one of the optical options used in childhood myopia management.

SNEC lists night-time Ortho-K alongside other myopia control approaches. The most appropriate option depends on the individual child and should be determined after professional assessment, which is what our Ortho-K assessment in Singapore covers.

Ortho-K does not involve removing or permanently altering corneal tissue.

Its effects are temporary, so discontinuing the lenses allows the eye to gradually return towards its previous refractive state.

This may appeal to people who want an alternative to permanent refractive procedures.

Suitable for Active Lifestyles

Glasses and daytime contact lenses are not always convenient during sports and other physical activities.

Because Ortho-K lenses are removed in the morning, successful wearers may be able to participate in daytime activities without depending on glasses or contact lenses.

Who Is Suitable for Orthokeratology?

Ortho-K is generally considered for people with myopia within a correctable range who prefer not to depend on glasses during the day, and for children where slowing myopia progression is part of the treatment goal.

Not everyone is suitable. Corneal shape and health, prescription, dry-eye symptoms, previous eye infections, allergies and the ability to maintain consistent lens hygiene all affect whether Ortho-K is appropriate, and none of these can be determined without an examination.

Orthokeratology for Children

One of the most common reasons parents consider Ortho-K is childhood myopia.

Myopia can continue progressing as a child grows, which is why simply correcting blurred vision is not always the only consideration. The rate at which the prescription and axial length are changing may also need to be monitored, and both MOH and SNEC recognise Ortho-K as one of the treatment options used in childhood myopia management.

For children using Ortho-K, parental involvement is especially important.

Parents should help ensure that the child:

follows the recommended lens wearing schedule;
washes and dries their hands properly before handling the lenses;
cleans and stores the lenses correctly;
does not continue wearing lenses when experiencing unusual pain, redness or irritation; and
attends scheduled follow-up examinations.

Myopia control treatment should accompany healthy eye care habits rather than replace them. Regular outdoor activity is part of Singapore’s broader approach to delaying the onset and progression of childhood myopia.

Orthokeratology for Adults

Ortho-K is not exclusively for children.

Adults may also use Ortho-K primarily for daytime vision correction, provided their prescription, corneal condition and overall eye health are suitable.

It can be particularly attractive to people who:

do not want to wear glasses during work, exercise or sports;
prefer not to use daytime contact lenses;
are not ready for permanent refractive surgery; or
simply prefer a reversible form of vision correction.

However, the reasons for prescribing Ortho-K in adults may differ from those in children. In children, slowing myopia progression may be an important treatment objective, while adults commonly use Ortho-K primarily for refractive correction and freedom from daytime eyewear.

An eye care professional should assess whether Ortho-K is appropriate based on the person’s individual eyes and lifestyle.

What Are the Risks of Orthokeratology?

Ortho-K is non-surgical, but it is still a form of contact lens wear, and contact lenses are not completely risk-free.

Possible problems can include:

eye irritation
redness
corneal abrasions
inflammation
eye infection

Poor hand hygiene, contaminated lens cases, incorrect cleaning procedures and poorly fitted lenses can increase the likelihood of complications.

This is particularly important because Ortho-K lenses are worn overnight.

SNEC notes that night-time orthokeratology carries a higher infection risk than some other myopia control options because of overnight lens wear.

In Singapore, all contact lenses, powered or non-powered, must be prescribed and dispensed by registered optometrists or contact lens practitioners, and lenses with refractive power are regulated as medical devices. The Health Sciences Authority warns that lenses bought from unknown or unauthorised sources without a practitioner consultation can lead to eye infections, corneal ulcers or even blindness.

Following the recommended cleaning routine and aftercare schedule is therefore an important part of successful Ortho-K wear.

How Are Ortho-K Lenses Fitted?

Ortho-K lenses are not an off-the-shelf product. Because corneal shape varies from person to person, each lens is designed around an individual eye.

The fitting process normally begins with a comprehensive evaluation of vision and eye health. Corneal topography is used to create a detailed map of the shape and curvature of the cornea. This determines whether the eyes are suitable for Ortho-K and guides the design or selection of the lenses.

Once the lenses are made, their position and fitting characteristics are assessed on the eye before they are dispensed. The practitioner will also teach lens handling and care at this stage.

Follow-up examinations are particularly important in the early stages. Vision does not usually reach its final corrected level after the first night, and the corneal response generally needs to be monitored over subsequent nights and visits before the result stabilises.

How to Wear Ortho-K Lenses

Always follow the instructions given by your optometrist or contact lens practitioner, as the recommended routine differs depending on the lens design and your individual eye condition.

In general, the lenses are inserted with clean, dry hands after inspecting each lens for deposits or damage, worn for the recommended overnight period, then removed in the morning and cleaned, disinfected and stored using the products your practitioner recommends. Do not use a lens that is damaged, contaminated or causing unusual discomfort.

If you experience persistent redness, pain, light sensitivity or blurred vision, remove the lens and seek professional advice.

For step-by-step handling and maintenance guidance, read our full guide on how to clean and store Ortho-K lenses.

Ortho-K vs LASIK: What Is the Difference?

Both Ortho-K and LASIK aim to reduce dependence on glasses or contact lenses, but they achieve this in very different ways.

	Ortho-K	LASIK
Method	Specialised overnight contact lenses	Refractive eye surgery
Corneal change	Temporary	Permanent
Surgery required	No	Yes
Reversible	Generally yes	No
Daytime glasses	May not be required after successful overnight wear	May not be required after successful surgery
Children	May be considered for suitable children	Generally not performed while the child’s eyes are still developing
Ongoing treatment	Regular lens wear and aftercare required	No ongoing lens wear required for the surgical effect

Ortho-K and LASIK should not be viewed as interchangeable treatments.

For children, myopia control is often an important consideration. For adults, the choice may be influenced more by prescription, eye health, lifestyle and whether they prefer temporary or permanent vision correction.

How Long Do the Effects of Ortho-K Last?

The duration of clear vision after overnight Ortho-K wear varies between individuals.

Most wearers report clear daytime vision lasting roughly 24 to 72 hours after each overnight wear. Some maintain good vision after a single night, while others notice their vision becoming gradually blurrier as the cornea begins to return towards its original shape.

Because the treatment is temporary, most users need to continue wearing their lenses according to the schedule recommended by their practitioner.

The frequency required will depend on factors such as:

the amount of refractive correction
individual corneal response
lens design
treatment progress

Ortho-K does not permanently correct the underlying refractive condition. This is particularly important in childhood myopia, where the aim is to help slow its progression rather than stop or reverse it completely. Regular eye examinations are therefore still important to monitor changes in prescription, eye growth and overall eye health.

Does Orthokeratology Permanently Correct Myopia?

Ortho-K temporarily changes the shape of the cornea. It does not permanently eliminate the underlying refractive condition.

This distinction is particularly important when discussing childhood myopia.

The goal of myopia control treatment is to slow progression, rather than guarantee that myopia will stop completely or disappear.

Regular eye examinations remain important so that changes in prescription, eye growth and overall eye health can continue to be monitored.

What Should You Expect After Starting Ortho-K?

During the first few days or weeks of Ortho-K wear, your vision may continue to change as your eyes adjust to the treatment.

Some people achieve clearer daytime vision relatively quickly, while others may require additional fitting adjustments or more time for the effect to stabilise.

Follow-up visits allow your practitioner to check whether the lenses are fitting properly and whether your eyes remain healthy.

For a more detailed explanation of the adjustment period, read our guide on what to expect after wearing overnight Ortho-K lenses.

Considering Orthokeratology in Singapore?

Whether Ortho-K suits you or your child can only be determined by an examination. If you want to find out, see our Ortho-K assessment and fitting in Singapore, which covers suitability, lens fitting, follow-up care and pricing.

FAQs

How often should Ortho-K lenses be replaced?

Ortho-K lenses are typically replaced every 12 to 24 months, depending on their condition, maintenance and your optometrist’s recommendation. Regular check-ups help determine when replacement is needed

Can you wear Ortho-K lenses too long?

Ortho-K lenses are usually worn overnight for 6 to 8 hours. Wearing them longer than recommended or using damaged lenses may increase the risk of eye irritation and infection. Always follow the wear schedule prescribed by your optometrist.

What are the long-term effects of Ortho-K lenses?

Ortho-K can provide clear daytime vision without glasses or contact lenses and may help slow myopia progression in children.

The effects of corneal reshaping are temporary, and vision gradually returns to its previous prescription after stopping ortho-K wear. However, improper lens care can increase the risk of eye infections. Regular check-ups and good lens hygiene are essential for safe, long-term use.

Are Ortho-K lenses suitable for children?

Ortho-K may be suitable for children and teens, particularly those with progressive myopia. The lenses are worn overnight and removed in the morning, allowing children to enjoy clear daytime vision without glasses or contact lenses. An eye assessment is required to determine suitability.

How much do Ortho-K lenses cost in Singapore?

Cost depends on your prescription, the lens design required and how much follow-up care is needed. The fee generally covers the initial assessment and corneal mapping, the customised lenses and the follow-up appointments while vision stabilises. For current pricing, see our Ortho-K service page.

About Philip D. Izaac

Dip. Optom. | B.Sc. Optom. (USA) | M.Sc. in Clinical Optom. (USA) | MOH Reg. No. E0801695J

Philip D Izaac has practised optometry since 1988 and specialises in contact lens fitting, an interest he developed in the early 1980s when rigid and soft lenses first came into wider use. He holds a Master of Science in Clinical Optometry from Pennsylvania College of Optometry, Salus University, USA, and is registered with the MOH Optometrists & Opticians Board.

He fits Ortho-K lenses at his practice in Singapore and sees patients for myopia management, complex contact lens cases and general eye care.

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