Novel multiregion spectacle lenses versus HAL for myopia control

Paper title: Myopia Control Efficacy of Grid Dimension Multiregion Spectacle Lenses: A One-Year Randomized Double-Masked Controlled Trial

Authors: Wang J (1), Lu W (1), Chen R (1)

1. National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China

Date: Published online February 24, 2026

Reference: Wang J, Lu W, Chen R. Myopia Control Efficacy of Grid Dimension Multiregion Spectacle Lenses: A One-Year Randomized Double-Masked Controlled Trial. J Ophthalmol. 2026 Feb 24; 2026:3220557

[Link to open access paper]

Grid dimension multiregion (GDM) spectacle lenses are a novel myopia control design developed to combine peripheral myopic defocus with induced high-order aberrations within a single lens. The design incorporates a microlens array to induce approximately 5.0-6.0D of myopic defocus and microcylindrical elements to generate directional blur, whereas highly aspherical lenslet (HAL) lenses use 11 concentric rings of 1.1 mm aspherical lenslets to create a volume of myopic defocus across the peripheral retina.

This prospective, randomised, double-masked trial enrolled 150 Chinese children (6-13 years, -0.75D to -5.00D myopia) comparing GDM lenses (5.0-6.0D defocus with microlenses and microcylindrical elements) against HAL lenses (3.5-5.0D defocus from aspherical lenslets). Primary outcomes were cycloplegic spherical equivalent refraction and axial length changes at 6 and 12 months. 

Key study findings were as follows.

• At 12 months, GDM lenses produced 0.07mm±0.17mm axial elongation versus 0.11±0.15mm for HAL lenses (adjusted p=0.048), representing a 0.04mm difference
• Spherical equivalent progression was similar between groups at 12 months (GDM: -0.17±0.40D, HAL: -0.19±0.36D, p=0.980)
• GDM lenses showed increased superior spherical equivalent control at 6 months (+0.06D vs -0.06D, p=0.042), but this advantage disappeared by 12 months
• Approximately 40% of children in both groups showed no myopia progression, with 37% of GDM and 25% of HAL participants showing no axial elongation
• Both lens types demonstrated good tolerability with minimal visual quality complaints and no adverse events reported

GDM and HAL spectacle lenses provided comparable myopia control in Chinese children aged 6-13 years (approx. 40% of both groups showed no myopia progression over a year). The axial length difference with novel GDM lenses (0.04mm over one year) suggests a modest increase in treatment effect from combining higher-order aberration control and myopic defocus, although it had borderline significance. However, initial increased refractive control with GDM lenses at 6 months was not sustained at 12 months, indicating that treatment effects may diminish over time. This suggests that the GDM design does not currently offer a clear advantage over HAL lenses and may not justify preferential selection without further evidence on long-term performance. 

The authors suggest that the reduced refractive control efficacy after 6 months may be due to visual adaptation to blur, which may reduce the treatment effect over time regardless of lens type worn. 

A proportion of children did not respond to treatment from either lens design. This highlights the importance of discussing realistic treatment trajectories with parents and patients before commencing myopia management and of the need for regular monitoring in clinical practice to identify individual non-responders. 

The underlying mechanisms of the GDM design, which incorporates myopia defocus with high-order aberration control were inferred from their design rather than measured through wavefront analysis and the relative contribution of each component remains unclear. The observed reduction in efficacy over time may reflect blur adaptation, although further research is needed to explore dose–response relationships and determine whether a threshold exists beyond which additional optical stimulus provides limited benefit.

The absence of a single-vision control group prevents evaluation of the absolute treatment effect for either lens type and limits interpretation to relative comparison only. Longer-term studies could determine whether diminishing efficacy represents temporary adaptation or sustained decrease of treatment benefits over time. 

Some within-group correlation was found between age and axial length change in the HAL group, but not the GDM group, suggesting there may be age-dependent responses. Larger studies objectively measuring visual quality across several age stratifications are needed to identify predictors of treatment response and guide individualised myopia management. 

Purpose: To evaluate the effectiveness and safety of grid dimension multiregion (GDM) spectacle lenses in myopia control and compare the myopia control effects between GDM and highly aspherical lenslets (HAL) spectacle lenses.

Methods: A total of 150 children aged 6-13 years were enrolled at the Hangzhou Campus of Eye Hospital of Wenzhou Medical University between December 2022 and July 2023 and randomly assigned to the GDM and HAL groups. Cycloplegic autorefraction (spherical equivalent refraction [SER]) and axial length (AL) were measured at baseline and 6-month intervals until one year follow-up.

Results: 131 participants completed the study and were included in the final analysis. At the six-month follow-up, the changes in SER and AL were 0.06 ± 0.37 D and 0.01 ± 0.11 mm in the GDM group and -0.06 ± 0.31 D and 0.04 ± 0.11 mm in the HAL group, respectively. The GDM group showed a statistically significant difference in SER changes compared to the HAL group (p = 0.042). No statistically significant difference in AL was observed between the groups (p = 0.266). At the one-year follow-up, the changes in SER were -0.17 ± 0.40 D in the GDM group and -0.19 ± 0.36 D in the HAL group. The changes in AL were 0.07 ± 0.17 mm in the GDM group and 0.11 ± 0.15 mm in the HAL group. No statistically significant differences in SER or AL were observed between the GDM and HAL groups (p = 0.980 and p = 0.131, respectively). After adjustment using generalized estimating equations, a significant difference in AL change was observed between the GDM and HAL groups (p = 0.048). In terms of subjective visual quality, there was no statistical difference in the total scores between the GDM and HAL groups (p = 0.436). No adverse events were reported in any group.

Conclusions: Both GDM and HAL lenses effectively controlled myopia progression over 1 year, with GDM showing slightly superior efficacy in limiting axial elongation.

[Link to open access paper]