EDUCATIONAL TOOL · NO DATA LEAVES THIS PAGE

Axial Length Lab

Place a measured axial length on a published centile chart for age and sex, then model refractive trajectory scenarios as a separate, optional step.

SCOPE OF THIS TOOL

This is an educational instrument. It is not an automated diagnosis, not an individual prognosis and not a treatment recommendation. Axial length is never converted into dioptres.

01
MEASURED VALUES

Enter the child's data

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YEARS
3 YEARS 16 YEARS
Sex
Prescription

Copy sphere, cylinder and axis exactly from the prescription. The spherical equivalent is derived per eye.

{{ eye.name }} {{ eye.code }}
D
D
°

Axis is required only when the cylinder differs from 0.00 D. The up arrow increases myopia, moving from zero towards negative values.

Myopia in the parents
+ Optical biometry available — enter axial length

Axial length appears on the printout of an optical biometer, not on a spectacle prescription. It is compared against the centile reference for age and sex and is never converted into dioptres.

The reference data cover children from age 6. For a younger child a centile cannot be obtained by extending curves for older children backwards. The measurement is shown, but no centile is calculated.
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COMPUTED LOCALLY · NOTHING IS STORED OR SENT

Waiting for data

Fill in age, sex and the prescription values, then run the analysis. Axial length is optional and produces a separate centile read-out.
02
ENTERED STATE

Spherical equivalent per eye

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03
BIOMETRY

Axial length on the centile chart

EUROPE + AUSTRALIA
The reference data cover children from age 6

A centile cannot be obtained for a younger child by extrapolating curves that describe older children. The measurements are shown without a centile.

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{{ centileChartTitle }} AL / mm · AGE / YEARS
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P2P50P75P97

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The centile follows from the entered biometry and does not change when a therapy scenario is selected. Colour indicates position in the reference distribution — it is not a diagnosis and not an indication for any specific therapy.

HOW TO READ AN AXIAL LENGTH CENTILE ＋

A centile places the axial length against children of the same sex and similar age in the reference population. A result on the 90th centile means the measurement is larger than in roughly 90% of that reference group.

One measurement does not show a rate of progression. Assessing dynamics requires repeat measurements taken under comparable conditions.

A high centile is not a diagnosis on its own. Its meaning depends on cycloplegic refraction, earlier measurements, the rate of ocular growth and examination of ocular structures.
04
OPTIONAL · SCENARIO MODEL

Refractive trajectory to age 20

TWO SCENARIOS · NOT A DIAGNOSIS
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AT AGE 20 · NO ACTIVE CONTROL
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Age-banded baseline rate plus the parental-history addition of 0.00 D, −0.15 D or −0.30 D per year.

AT AGE 20 · {{ scenarioLabelUpper }}
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How to read the chart: solid markers show the entered prescription. Dashed lines show two model scenarios. The scale runs from 0 to −18 D, so increasing myopia moves upwards. Axial length is not part of this simulation and is never converted into dioptres.

05
OPTIONAL · RESPONSE TO THE RESULT

Apply a myopia-control scenario

Select one method or combine two. The trajectory above recalculates immediately. Each percentage is an explicit model parameter drawn from published syntheses, not a measured effect for an individual child.

Atropine and RLRL must not be combined on your own initiative. {{ conflict }}

Permitted combinations in this model: defocus optics + RLRL, and defocus optics + atropine 0.01%. Concurrent RLRL and atropine requires special attention →

!
Uncontrolled progression carries long-term consequences.

Progressive myopia can reach high myopia and raise the risk of sight-threatening complications, including retinal detachment, myopic maculopathy and glaucoma. Refractive value alone does not diagnose pathological myopia — biometry and examination of ocular structures are required.

FULL PARAMETERS USED IN THE SIMULATION ＋
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{{ assumptionSummary }} The coefficients harmonise results reported in dioptres and in millimetres of axial elongation without converting millimetres into dioptres. They are scenario parameters, not a guarantee of clinical effect, and they are held in one place so they can be audited and replaced when a source set is agreed.

Basis: IMI — Interventions for Controlling Myopia Onset and Progression 2025; Cochrane living systematic review 2025, CD014758; Luo et al. 2025, RLRL + DIMS, doi:10.1016/j.pdpdt.2025.104681.