What is Ortho-K? Lenses for Myopia Control (Night Lenses)
Author: Jason Higginbotham
BSc (Hons) MCOptom Prof Cert Glau Prof Cert Med Ret Prof Cert LV FBDO MBCLA
An Introduction to Orthokeratology. Hard contact lenses for myopia control and management.
What is Ortho K or night lenses?
Orthokeratology, usually shortened to Ortho K, uses custom made rigid gas permeable contact lenses that are worn overnight. While your child sleeps, the lenses gently reshape the front of the eye (the cornea) so that, by morning, light focuses correctly on the retina.
The result is:
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Clear vision through the day
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No need for glasses or daytime contact lenses
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A significant myopia control effect in many children
The effect is temporary. To keep vision clear and maintain myopia control, lenses need to be worn most nights.
Simply put, 'ortho' means 'straightening' and 'keratology' refers to the cornea, so 'ortho-k' is a way to straighten the cornea to temporarily correct myopia and reduce the risk of progression.
Every evening, the lens is put back in the eye after being cleaned during the day. Ortho-K can give many children freedom from glasses or contact lenses during the day.
In this guide:
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Expert and advisory views - Coming Soon
TL;DR Key Points
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What are Ortho K night lenses?
Special rigid contact lenses your child wears while they sleep. Overnight, they gently reshape the clear front surface of the eye (the cornea), so your child can see clearly in the day without glasses or daytime lenses.
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Do they help with myopia?
Yes. Ortho K does two jobs: it corrects vision and it slows down how quickly short sightedness (myopia) gets worse. Studies suggest it can cut progression by around 50 percent compared with standard single vision glasses or lenses.
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Are Ortho K lenses safe for children?
Large long term studies show Ortho K is a safe and predictable option for children when lenses are fitted by an experienced practitioner, hygiene is excellent and regular check ups are kept.
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Who is Ortho K good for?
Active children, those who dislike wearing glasses, or families who want a strong myopia control option that parents can supervise at home. Not every prescription or child is suitable.
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Is it available on the NHS?
Ortho K fitting is usually a private service in the UK, although your child may still receive an NHS sight test. Fees and plans vary between practices.
How do Ortho K lenses work?
A simple way to picture it:
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The cornea is like a clear window with gentle curves that help focus light.
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In axial myopia, the eye’s focusing system and length are not in balance, so light focuses in front of the retina instead of directly on it.
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Ortho K lenses are designed to flatten the central cornea very slightly and alter the shape in the mid-peripheral area. This reduces the focusing power so light lands where it should.
What happens in practice:
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Your child applies the Ortho K lenses before bed.
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As they sleep, the lenses stay centred on the cornea, helped by the closed lids.
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By morning, the front of the eye has been gently reshaped.
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Your child removes the lenses and can usually see clearly all day.
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If they stop wearing the lenses, the cornea gradually returns to its previous shape over a few days and their usual myopia returns.
Ortho-K
Advantages
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Parents can monitor and control the handling of lenses, reducing the risk of eye infections.
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Lenses offer convenience and freedom from wearing corrective eyewear throughout the day.
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Children may be more likely to spend time outdoors and engage more in outdoor pursuits and sports.
Disadvantages
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Some individuals may require an adaptation period to get used to wearing Ortho-K lenses during sleep.
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Can initially cause discomfort or dryness
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Strict wearing schedule required
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More expensive than traditional contact lenses or glasses
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Additional equipment and training required
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Only effective over a narrow prescription range
FOCUSPOINT
Simply put, 'ortho' means 'straightening' and 'keratology' refers to the cornea, so 'ortho-k' is a way to straighten the cornea to temporarily correct myopia
Can Ortho K really slow myopia in children?
Yes. Ortho K is not just a clever way to avoid glasses. It has been one of the best studied myopia control treatments for children.
What the research says
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A 2023 meta analysis of Ortho K in children concluded that Ortho K delays the progression of myopia, significantly reducing eye length growth compared with standard corrections.
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Multiple clinical trials and reviews indicate Ortho K slows myopia progression by around 50 percent on average compared with single vision glasses or contact lenses.
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Newer analyses continue to place Ortho K among the most effective options in head to head comparisons of myopia control treatments.
In plain language, this means that in many children: With Ortho K, their prescription still increases over the years, but roughly at half the speed it would have without treatment.
Because higher levels of myopia are linked with a greater risk of eye problems such as retinal detachment and myopic maculopathy later in life, keeping the diagnosis as low as possible is an important long term health goal.
How safe is Ortho K for my child?
This is usually the first question parents ask, and rightly so.
Long term safety
An 18 year follow up study of people using Ortho K found that it is a safe and predictable long term procedure in both children and adults, with a low incidence of serious adverse effects. The most common issue was mild corneal staining, which was usually manageable with lens care advice or short breaks from wear.
Reviews and real world studies up to 2024 and 2025 also conclude that:
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Ortho K is a safe option for myopia control in children, provided lenses are fitted by suitably trained practitioners and hygiene instructions are followed.
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Serious infections such as microbial keratitis are rare in children, and overall risk is similar to, or lower than, some extended wear soft lens modalities when care is good.
The biggest safety risks
Most complications in Ortho K are linked to:
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Poor cleaning routines
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Sleeping in lenses that are not fitting correctly
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Allowing lenses or cases to come into contact with water
Acanthamoeba, a micro-organism found in tap water and other water sources, can cause a serious corneal infection (Acanthamoeba keratitis) if it gets trapped under a lens. This is why modern guidance is very clear:
Lenses, cases and any lens accessories should never be rinsed with tap water, and lenses should not be worn in swimming pools, hot tubs or the shower.
With good hygiene, no water contact and regular check ups, Ortho K has a strong safety record in children.
Who is Ortho-K suitable for?
Suitability always needs to be assessed by an optometrist or eye doctor trained in Ortho K, but as a rough guide it tends to work best when:
1. Your child’s prescription is in range
Typical ranges (these are guides, not rules):
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Myopia up to around −4.50 dioptres, sometimes higher with specialist designs
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Astigmatism up to about −1.50 dioptres in many standard designs
Other factors such as corneal shape and eye health also matter, which is why corneal topography and a full eye examination are essential.
2. Your child and family can manage the routine
Ortho K can be an excellent choice if:
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Your child is reasonably responsible and can cope with a simple bedtime routine
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You, as the parent, can supervise lens application, removal and cleaning, especially in the early months
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You can attend follow up appointments as advised
3. Lifestyle and personality fit Ortho K
Ortho K often works particularly well for:
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Children who play a lot of sport or outdoor activities
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Those who dislike wearing glasses or struggle with daytime soft contact lens wear
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Families who are highly motivated to slow myopia progression and are willing to invest time and money into a structured treatment
Children with certain eye conditions or very high prescriptions may not be suitable. Your practitioner will advise.
FOCUSPOINT
Ortho K is a spcialist product. Suitability always needs to be assessed by an optometrist or eye doctor trained in Ortho K
How does the fitting process of Ortho K work?
A typical journey in UK practice looks like this:
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Assessment and suitability visit
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Full eye examination and refraction
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Corneal topography (a special scan that maps the front of the eye in detail)
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Discussion of expectations, lifestyle and ability to manage lens care
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Lens design and ordering
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The practitioner uses the corneal map and prescription to order or design a bespoke Ortho K lens for your child.
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Collection and teaching appointment
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Your child learns how to apply, remove, clean and store the lenses
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You are shown how to supervise and support them at home
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First overnight check
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Seen the next morning to check the fit, corneal response and early vision result
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This gives an early indication of how well the treatment will work
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One week to one month review
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By around a week, many children are close to their full correction, although for some it takes a little longer
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Vision, comfort, corneal health and lens fit are checked
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Ongoing care
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Once stable, reviews are usually every 6 months, sometimes more often in the first year
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Many UK practices include these aftercare visits in a monthly care plan
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A real-life example of how Ortho-K can slow down myopia progression
On the right side of this page, you can find an interview-style video where Jason Higginbotham, Myopia Focus's Managing Editor and advisory committee member Sandip Doshi chat with Claire and her daughter Amelia.
Amelia was prescribed Ortho-K night lenses more than 7 years ago by Sandip, an optometrist and practice owner with over 30 years of industry experience. In the short video, she describes her experience with the night lenses and how they have positively improved her life and ultimately slowed down the progression of her myopia.
What will my child feel and notice
Wearing a rigid lens for the first time can feel quite different from a soft lens.
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When lenses first go in, your child may feel a sense of “lens awareness”, like a small piece of dust under the lid. This usually eases over a few nights.
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Once their eyes are closed and they fall asleep, most children forget the lenses are there.
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In the morning, vision may be a bit “soft” at first in the early days, then clearer as the treatment effect builds.
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Some children notice temporary glare or haloes around lights during the early weeks. This often settles as the cornea shape stabilises.
The key message for your child is:
“It might feel a bit strange at first, but it should not be painful. If anything hurts, we take the lenses out and tell the optometrist.”
Combining Therapies: Ortho K and Atropine
Low dose atropine eye drops are another evidence based treatment to slow myopia progression. The recent announcement that an atropine drop has been made available in the UK, is great news, particularly as again the evidence shows that combining atropine with Ortho K can be even more effective.
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A 2 year randomised clinical trial (the AOK study) found that 0.01 percent atropine combined with Ortho K gave better myopia control than Ortho K alone in children, with additional reduction in axial length growth.
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A 2024 trial also reported that Ortho K plus 0.01 percent atropine reduced eye elongation more than Ortho K with placebo drops, although there were some additional changes in tear film and corneal epithelium that need monitoring.
Combination therapy is not necessary for every child, but your specialist may raise it if your child’s myopia is progressing rapidly or if they are at higher risk.
Frequently Asked Questions about Ortho K
Discuss a Myopia Management Plan with a local specialist.
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Key research and references
For parents who like to see the evidence:
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Li X et al. Orthokeratology in controlling myopia of children: meta analysis, 2023.
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Gispets J et al. Efficacy, predictability and safety of long term orthokeratology: 18 year follow up study, 2022.
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Zheng Z et al. Myopia control strategies: systematic review and network meta analysis, 2025.
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Tan Q et al. Combined 0.01 percent atropine with orthokeratology in childhood myopia control (AOK study): 2 year randomised clinical trial, 2022.
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Li B et al. Effect of 0.01 percent atropine combined with Ortho K on axial elongation in schoolchildren: randomised trial, 2024.
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Wang F et al. Factors influencing effectiveness of Ortho K in controlling myopia in children, 2025.
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MyKidsVision and Myopia Profile clinical summaries on Ortho K safety and efficacy.