Orthokeratology - often shortened to Ortho-K - is a safe, non-surgical way of correcting vision by gently reshaping the surface of the eye while you sleep. By wearing specially designed contact lenses overnight, the cornea adopts a new shape by morning, allowing you to see clearly during the day without glasses or daytime contact lenses.

Unlike permanent procedures such as laser eye surgery, Ortho-K is completely reversible: if you stop wearing the lenses, the cornea gradually returns to its original shape within days. This makes it a flexible option for both children and adults, and one of the most exciting tools we have for myopia control in younger patients.

How Ortho-K Works

The word "orthokeratology" literally means reshaping (ortho) of the cornea (keratology). The process does not involve cutting, burning, or surgically altering the eye. Instead, Ortho-K lenses apply gentle pressure to the tear film and the very top layer of cells on the eye (the epithelium).

• Not bending the cornea: A common misconception is that Ortho-K "bends" the cornea into a new shape. In reality, it works by redistributing epithelial cells, thinning some areas and thickening others by a matter of microns (a fraction of a millimetre).

• Precision shaping: This creates a new optical profile that corrects the way light focuses in the eye, bringing vision into clear focus during the day.

• Reversible changes: Because the reshaping only affects surface cells, the effect is temporary and reversible. The cornea naturally returns to its baseline within a few days if the lenses are not worn.

Suitability for a Variety of Prescriptions

Modern Ortho-K is not limited to mild prescriptions. With advances in lens materials and computer-guided design software, it is now possible to correct:

• Myopia (short-sightedness): typically up to –6.00D, sometimes higher in selected cases.

• Low to moderate astigmatism: up to about –1.50 to –2.00D, depending on corneal shape.

• Low hyperopia (long-sightedness): in certain cases.

Because every cornea is unique, suitability depends not just on the prescription but also on the shape and health of the corneal surface, which we evaluate thoroughly before recommending treatment.

Myopia Control Benefits

One of the most important discoveries in eye care over the past two decades is that Ortho-K does more than just correct vision. In children and teenagers, it can also help to slow the progression of myopia (short-sightedness).

• How it works: Ortho-K lenses create a unique peripheral corneal profile that alters how light focuses in the back of the eye (the retina). This change in optical signalling reduces the stimulus for eye growth, which is the main driver of worsening myopia.

• Evidence base: Multiple peer-reviewed studies have shown that Ortho-K can reduce myopia progression by 30–60% on average compared with standard glasses or soft lenses (Charm & Cho, 2013; Walline, 2016).

• Long-term benefits: Slowing myopia progression is about more than clearer vision today. High levels of myopia are associated with an increased lifetime risk of conditions like retinal detachment, glaucoma, and myopic maculopathy. By reducing progression, Ortho-K may lower these future risks.

Healthy Ocular Surface: A Key Requirement

For Ortho-K to work effectively and safely, the ocular surface must be healthy. Because the lenses rest on the eye overnight, issues like dry eye disease, lid inflammation, or allergies need to be identified and managed first.

Every Ortho-K candidate should undergo a comprehensive pre-fit assessment:

• Corneal topography (mapping the corneal surface).

• Ocular surface evaluation (tear film, lid health).

• General eye health screening.

If we detect underlying issues, such as meibomian gland dysfunction or allergy, we recommend treatment before starting Ortho-K. This ensures not only a safer experience but also better and more stable vision outcomes.

Topography-Guided Lens Design

Modern Ortho-K is vastly different from early versions used in the 1980s and 90s. Today, lenses are custom-designed using computerised corneal topography.

• Precision fit: The topography map acts like a “fingerprint” of your cornea, allowing us to design a lens that matches your unique shape.

• Higher accuracy: Software-guided designs give better centring, faster visual results, and greater comfort.

• Safety improvements: High oxygen-permeable (high Dk) lens materials reduce the risk of hypoxia (oxygen deprivation).

This technology has transformed Ortho-K into a reliable and mainstream treatment option used worldwide.

What Ortho-K Feels Like

Because the lenses are worn overnight, most patients do not feel them while sleeping. There may be some initial awareness when they are first inserted, but this sensation usually fades within minutes. By morning, the lenses are removed, and patients enjoy clear vision all day long without glasses or contact lenses.

For children, this can mean being able to play sport, swim, or go to school without worrying about glasses. For adults, it can mean freedom from daytime contact lenses in dusty work environments, sports, or travel.

Safety and Compliance

Ortho-K is generally very safe when fitted and monitored by an experienced optometrist. However, like all contact lens wear, it requires good hygiene and compliance. Risks include infection or corneal staining if lenses are not cleaned properly or worn as directed.

We educate every patient (and every parent) in:

• Proper lens insertion and removal.

• Daily cleaning and disinfecting routines.

• The importance of regular aftercare visits.

With good compliance, the risk profile of Ortho-K is similar to that of other forms of contact lens wear

Orthokeratology was first developed as a way to give people freedom from glasses and contact lenses during the day. Over time, research has shown that Ortho-K has an even bigger role to play in slowing the progression of myopia in children. Today, it is used in a wide variety of situations, from everyday short-sightedness to more specialised cases.

Children and Teenagers with Myopia

The most common candidates for Ortho-K are children and adolescents who are becoming more short-sighted each year. These lenses not only provide clear daytime vision without glasses, but also create a unique corneal profile that has been shown to slow down myopia progression by 30–60% in most studies.

Parents often find Ortho-K appealing because it combines freedom for sport, school, and daily activities with the long-term benefit of protecting eye health. The earlier treatment is started, the greater the potential to reduce the final level of myopia.

Adults Who Want Freedom from Glasses or Lenses

For adults who are not interested in laser eye surgery, or for those who work in dusty, dry, or challenging environments, Ortho-K offers an attractive alternative. Many adults choose it for sports, swimming, or outdoor work, where glasses and soft lenses are inconvenient or less safe.

Because Ortho-K is reversible, it also appeals to adults who want flexibility, or who may not be suitable for surgery due to corneal thickness or other medical factors.

Post-Laser Surgery Regression

In some patients who have previously undergone LASIK or PRK, vision can slowly regress over time. While repeat laser procedures are not always an option, Ortho-K can sometimes be used to fine-tune or restore vision in these eyes. Careful assessment of the corneal shape and health is required, but in selected cases, this can provide a non-surgical solution for post-laser progression.

Astigmatism

Modern Ortho-K designs can also correct mild to moderate levels of astigmatism (generally up to –1.50 to –2.00 dioptres) in conjunction with myopia. Special toric Ortho-K lenses are used, customised to the individual’s corneal shape. This means patients who were once excluded from Ortho-K can now enjoy its benefits.

Hyperopia (Farsightedness)

Although less common, Ortho-K can also be used in cases of low hyperopia (less than +2.50 dioptres). These lenses gently reshape the cornea to bring near and distance vision into better focus. Outcomes in hyperopia are not as predictable as in myopia, so careful patient selection and expectation management are important.

Presbyopia (Experimental / Developmental Use)

One of the more exciting areas of development in Ortho-K is the use of multifocal designs for presbyopia (the age-related loss of near vision that typically begins in the 40s). These lenses aim to reshape the cornea in a way that provides clearer distance and near vision simultaneously. While still considered experimental and not as widely available as myopia-focused designs, they represent a promising option for the future.

Starting orthokeratology is an exciting step — it offers the freedom of clear vision without glasses or daytime lenses. Like any treatment, success with Ortho-K comes from understanding the process, giving your eyes time to adapt, and attending regular check-ups.

The First Consultation

Your Ortho-K journey begins with a comprehensive eye examination. We measure:

• Your exact prescription.

• The shape and thickness of your cornea using corneal topography.

• The health of your ocular surface (tear film, eyelids, general eye health).

This allows us to determine if Ortho-K is suitable for you. If there are issues like dry eye or eyelid inflammation, we may recommend treatment first to ensure the best results.

Lens Design and First Fitting

Using your topography maps, we design a pair of custom-made Ortho-K lenses tailored to your eyes. At your first fitting appointment, you’ll learn how to insert, remove, and care for the lenses.

Some awareness is normal at first, but because Ortho-K lenses are intended to be used while sleeping, comfort is rarely an issue.

The First Nights

After the very first night, most patients notice a significant improvement in vision, though it may not yet be perfect. Over the next 1–2 weeks, the reshaping effect becomes more stable, and daytime vision sharpens. Children often find this stage especially rewarding, as they can go to school or sports without glasses almost immediately.

Follow-Up Appointments

Follow-up is a key part of Ortho-K. In the early stages, we usually see you:

• After the first night of wear.

• After the first week.

• At 1 month, and then every few months after that.

During these visits we check lens fit, corneal health, and the quality of your vision. Adjustments are sometimes needed in the first few weeks to fine-tune the results.

Daily Routine

Wearing Ortho-K becomes part of your bedtime routine:

• Insert lenses before going to sleep.

• Remove them in the morning, clean them, and store them in solution.

• Enjoy clear vision all day without glasses or contact lenses.

To maintain results, lenses need to be worn most nights. Skipping a night or two may lead to a gradual softening of the effect, but vision quickly recovers once regular wear resumes.

Long-Term Care and Safety

Like all contact lenses, Ortho-K requires good hygiene. With proper cleaning and regular aftercare, Ortho-K is very safe, with a risk profile similar to other contact lenses. We teach every patient (and parents, if the wearer is a child) how to care for lenses properly to minimise the risk of infection.

Realistic Expectations

• Ortho-K can correct a wide range of short-sighted prescriptions, and in most cases gives clear daytime vision without glasses.

• Vision is usually stable for the whole day, though some patients may notice a little softening in the evening, especially during the early stages.

• Ortho-K is not a cure for myopia, but it can provide clear vision today and help slow down myopia progression in children.

While Ortho-K is a versatile tool, there are practical limitations and considerations that are important for case selection and long-term success.

Ideal Prescriptions

The most reliable results are achieved in patients with myopia between –0.75D and –4.00D and astigmatism less than –1.00D. These prescriptions allow for well-centred treatment zones and stable visual outcomes.

Higher Prescriptions and Limitations

In higher myopia and astigmatism, outcomes can be more variable.

• Smaller treatment zones may induce spherical aberrations. While neuroadaptation often improves subjective vision, the time course and effectiveness vary significantly between patients.

• Sagittal depth adjustments in higher prescriptions can result in lens decentration or instability. In these cases, it is common to require a second or third lens iteration to fine-tune the fit and achieve satisfactory vision.

Myopia Control Considerations

For low myopia, Ortho-K may not be as effective as other myopia control modalities. Although we can manipulate treatment zone diameter to enhance peripheral myopic defocus, atropine (low-dose) should often be considered as a first-line approach in this group.

Cylinder and Sphericalisation Effects

As Ortho-K tends to sphericalise the cornea, the impact of astigmatism is influenced by the spherical component. For example:

• A prescription of –0.75/–2.50 × 180 is more challenging to manage than –5.00/–2.50 × 180, where the larger spherical component balances the correction.
  This highlights the importance of case selection and realistic expectation setting in patients with higher astigmatism.

Age and Patient Receptivity

While there is no absolute minimum age for Ortho-K, in practice we find that children are most receptive and compliant from around 8 years of age. At this stage, they typically have the dexterity and maturity to handle lens care with appropriate parental support.