How Ortho-K Slows Myopia Progression in Children

If your child is short-sighted, you've probably been told it's just something they'll "grow out of" — or something glasses will fix. The truth is more complicated. Myopia in children tends to get worse over time, and standard glasses do nothing to slow it down. But Ortho-K can.

Here's what the science says about how Ortho-K controls myopia progression — and why it matters for your child's long-term eye health.

Why Does Childhood Myopia Get Worse?

Myopia occurs when the eyeball grows too long from front to back. Light entering the eye focuses in front of the retina instead of on it, making distant objects blurry.

In children, the eye is still growing. For myopic children, the eye grows faster than normal — and each millimetre of extra length translates to roughly -2.50 to -3.00 dioptres of additional myopia. This is why children who are diagnosed with myopia at age 7 often end up with much higher prescriptions by age 18.

The problem compounds: higher myopia means a longer eyeball, which means a thinner retina stretched over a larger surface area. This significantly increases the lifetime risk of:

• Retinal detachment — 3x increased risk per additional -1.00 dioptre
• Myopic macular degeneration — the leading cause of irreversible blindness in developed countries
• Glaucoma — higher risk throughout life
• Early cataracts

This is why simply correcting the blur with glasses isn't enough. Slowing the progression is what truly protects your child's eyes.

How Ortho-K Slows Eye Growth

Ortho-K lenses work by gently reshaping the central cornea overnight, which corrects the focus for distance vision. But the myopia control benefit comes from a different mechanism: peripheral defocus.

When a child wears standard glasses or contact lenses, light focuses sharply at the centre of the retina but falls behind the retina at the periphery (this is called peripheral hyperopic defocus). Research suggests this peripheral pattern sends a biological signal to the eye to keep growing longer.

Ortho-K changes this pattern. The reshaped cornea creates peripheral myopic defocus — light at the periphery focuses in front of the retina. This is believed to reduce the signal for the eye to elongate, effectively putting the brakes on growth.

What the Clinical Studies Show

The ROMIO Study (2012)

This landmark randomised controlled trial compared Ortho-K to standard glasses in children aged 6-10 over two years. The result: Ortho-K slowed axial eye growth by 43% compared to the glasses group.

The SMART Study

This multi-year study found Ortho-K reduced myopia progression by 36-56% depending on the child's age and initial prescription. Younger children with faster-progressing myopia showed the greatest benefit.

Meta-Analysis of 16 Studies (2015)

A comprehensive analysis combining data from 16 clinical studies confirmed that Ortho-K consistently slows axial length growth across different populations, age groups, and ethnicities.

Long-Term Follow-Up Studies

Research following children wearing Ortho-K for 5+ years shows that the myopia-slowing effect is sustained over time. However, the benefit is greatest when treatment begins during the period of fastest progression (typically ages 6-12).

What This Means in Practice

Let's make this concrete with an example. Consider a child diagnosed with -1.50 myopia at age 8, progressing at -0.75 per year (which is common):

• Without myopia control (glasses only): By age 18, predicted prescription of approximately -9.00
• With Ortho-K (assuming 50% slowing): By age 18, predicted prescription of approximately -5.25
• That's a difference of nearly -4.00 dioptres — which translates to significantly reduced lifetime risk of retinal disease, glaucoma, and macular degeneration

While every child is different and results vary, the pattern is consistent across studies: Ortho-K meaningfully reduces how myopic a child becomes.

When Should Myopia Control Start?

The general principle is: the earlier, the better. Myopia progression is typically fastest between ages 6-12, so starting Ortho-K during this window provides the greatest potential benefit. However, Ortho-K can provide meaningful myopia control at any age during the growing years.

Key indicators that a child would benefit from Ortho-K myopia control:

• Prescription is -0.75 or higher
• Prescription is increasing by -0.50 or more per year
• Family history of myopia (especially high myopia)
• High screen time and limited outdoor time
• Young age at first diagnosis (under 10)

Ortho-K Compared to Other Myopia Control Methods

Ortho-K is not the only myopia control option, but it's one of the most effective. Here's how it compares:

• Ortho-K: 36-56% slowing of myopia progression + provides full daytime vision correction. No daytime lens wear
• Low-dose atropine drops (0.01-0.05%): 30-50% slowing. Does NOT correct vision — child still needs glasses. Minimal side effects at low doses
• MiSight daily disposable lenses: 25-40% slowing. Worn during the day like regular contacts. Good for children who can manage daily contact lens wear
• Hoya MiyoSmart spectacle lenses: 20-60% slowing depending on the study. Worn as regular glasses. Good for younger children not ready for contacts
• Standard glasses: 0% slowing. Correct vision only

In some cases, combination therapy (e.g., Ortho-K plus low-dose atropine) may be recommended for children with very fast-progressing myopia. Our optometrists will discuss the best approach for your child.