Why measuring eye growth matters in childhood myopia

If your child’s glasses prescription keeps changing every year, you’re not alone. Many parents assume that stronger glasses are just part of growing up. But prescriptions only tell part of the story.

What actually matters most is how long the eye is growing.

That measurement is called axial length, and it has become one of the most important tools in modern myopia management.

At Merivale Vision Care, we use axial length measurement to better understand myopia progression, guide treatment decisions, and help families make informed choices—especially during the years when eye growth is most active.

What is axial length (in plain language)?

Axial length is the front-to-back length of the eye, measured in millimetres.

• A child’s eye naturally grows as they age
• In myopia (nearsightedness), the eye grows too long
• That excessive growth increases lifetime risk for eye health issues later on

Axial length tells us whether myopia is stable or still progressing—even when vision seems “okay.”

This measurement is painless, quick, and non-contact. Most kids find it easier than reading letters on the chart.

Why glasses prescriptions don’t tell the full story

A prescription measures how clearly your child sees today.

Axial length tells us what’s happening structurally inside the eye.

Here’s why that matters:

• Prescriptions can fluctuate with focusing effort and lighting
• Two children can have the same prescription but very different eye growth patterns
• Myopia can quietly progress even when vision seems stable

That’s why global myopia guidelines recommend tracking axial length—not just refraction.

“Axial length is one of the most reliable ways to monitor myopia progression over time.”
— International Myopia Institute [IMI]

Why eye growth matters for long-term eye health

Myopia isn’t just about needing glasses.

As axial length increases, the lifetime risk of eye disease also rises, including:

• Retinal detachment
• Myopic macular degeneration
• Glaucoma
• Early cataracts

Slowing eye growth during childhood and teenage years can reduce future risk, even if your child still needs glasses.

That’s why modern myopia care focuses on monitoring growth trends, not just vision clarity

How we use axial length at Merivale Vision Care

At Merivale Vision Care, axial length measurement is part of a thoughtful, data-guided approach to myopia management.

We use it to:

• Establish a baseline for your child’s eye growth
• Track changes over time (not just year-to-year prescriptions)
• Decide when to start, adjust, or continue myopia control strategies
• Have clearer, more objective conversations with parents

This helps avoid guesswork.

Families can see real numbers, real trends, and real reasons behind care decisions.

How often is axial length measured?

Most children in myopia management are monitored every 3–6 months, depending on age and growth rate.

This cadence is supported by international consensus guidelines [IMI].

“Regular axial length monitoring allows earlier detection of accelerated eye growth.”
— Myopia Profile

“Seeing growth patterns helps us fine-tune treatment instead of reacting late.”
— Spadina Optometry, Toronto

What parents can expect at a myopia monitoring visit

A typical myopia follow-up visit may include:

• Axial length measurement
• Prescription check (refraction)
• Eye health evaluation
• Review of growth trends over time
• Discussion of lifestyle factors (screen time, outdoor time)

If growth is faster than expected, we talk through options calmly and clearly—no pressure, no one-size-fits-all recommendations.

“Axial length helps us decide when to intervene and when to simply monitor.”
— Insight Eye Care, Waterloo

Common questions parents ask about axial length

Does axial length measurement hurt?

No. It’s non-contact and takes just seconds.

Can axial length replace glasses prescriptions?

No. They measure different things and work best together.

What’s considered normal eye growth?

Growth depends on age, genetics, and individual patterns. That’s why tracking trends over time matters more than one number.

Can axial length measurement stop myopia?

No test stops myopia. Monitoring helps guide strategies that may slow progression.

Is this recommended by professional organizations?

Yes. The International Myopia Institute and other optometry bodies emphasize axial length as a key endpoint in myopia management [IMI].

Why families in Ottawa are asking about axial length

More parents are learning that myopia care has changed.

Instead of waiting for prescriptions to worsen, families want:

• Earlier insight
• Objective measurements
• Fewer surprises year-to-year

Axial length measurement provides exactly that.

“Parents appreciate having something measurable to follow—not just ‘wait and see.’”
— Waverley Eye Care, Winnipeg

Where to get axial-length–based myopia monitoring in Canada

Ottawa — Merivale Vision Care
Toronto — Spadina Optometry
Waterloo — Insight Eye Care
Toronto — Bay Street Eye Care
Winnipeg — Eyes on Bridgwater
Calgary — Mission Eye Care
Winnipeg — Waverley Eye Care
Vancouver— Eye Lab

Thinking about myopia management for your child?

If your child’s prescription is changing—or you simply want better insight into their eye growth—we’re happy to talk.

You don’t need to decide everything at once.

Sometimes the first step is just measuring and understanding what’s happening.

Book a myopia consultation or learn more at Merivale Vision Care.

Medical disclaimer

This article is for educational purposes only and does not replace individualized medical advice. Myopia management recommendations vary by patient. Please consult your optometrist for personalized care.