Preliminary observations from opaque-feature contact lenses in myopia

Paper title: Contact lenses with non‑refractive opaque features for paediatric myopia: a randomised, safety pilot trial

Authors: Ravi C Bakaraju (1,2), Jennie Diec (3), Daniel Tilia (3,4), Klaus Ehrmann (3,4), Ranjay Chakraborty (5)

1. nthalmic pty ltd, Sydney, NSW, Australia. 
2. School of Optometry and Vision Science, UNSW, Sydney, NSW, Australia. 
3. nthalmic pty ltd, Sydney, NSW, Australia.
4. School of Optometry and Vision Science, UNSW, Sydney, NSW, Australia.
5. Myopia and Visual Development Lab, Caring Futures Institute, College of Nursing and Health Sciences, Flinders University, Adelaide, SA, Australia.

Date: Apr 2026

References: Bakaraju RC, Diec J, Tilia D, Ehrmann K, Chakraborty R. Contact lenses with non‑refractive opaque features for paediatric myopia: a randomised, safety pilot trial. Eye (Lond). 2026 Apr 22

[Link to open access paper]

Myopia control contact lenses typically use Myopia control contact lenses typically use optical defocus or light scatter to slow eye growth. This pilot study investigated a daily disposable soft contact lens design incorporating small opaque features within the central optic zone to modulate retinal light patterns during eye movement, without inducing defocus or blur. 

Six myopic children aged 7-15 years wore the test lens in one eye and a matched single-vision control lens in the fellow eye for 6 months, then crossed over for another 6 months, followed by 2 months of bilateral control lens wear. The test lens contained 28 rectangular opaque features within the central 5mm zone. Axial length, visual acuity and ocular health were assessed at two-month intervals.

Key study outcomes were as follows

• No corneal infiltrative events or vision-threatening adverse events were reported during the 14-month study period
• High-contrast visual acuity remained stable throughout the follow-up period
• No participant required a refractive prescription change during the study period
• Axial length patterns varied between participants, with no consistent pattern observed across all children(some showed initial slowing, and some no change)
• Some participants showed similar axial length patterns between eyes throughout follow-up

This study describes the use of contact lenses with opaque, non-refractive features in myopic children. Over 14 months, no clear evidence of accelerated eye growth or clinically significant ocular complications was observed, although the small sample size and early-stage study design mean these findings should be interpreted with caution and are insufficient to support definitive safety conclusions.

Slit-lamp examinations showed no clinically significant corneal complications, high-contrast visual acuity remained stable, and no participants required a change in refractive correction during the study period. These outcomes remain preliminary given the limited dataset.

Axial length changes varied between participants, with no consistent pattern observed across the study period. Confirmed and possible lens misassignment, together with variable adherence to lens wearing time, limit the clinical applicability of these findings, but lay the foundation for future, larger studies to further evaluate this novel optical concept.

The authors speculate that opaque features may act through a contrast-based mechanism rather than through optical defocus. However, this pilot study only assessed axial length and did not assess retinal responses or light patterns reaching the retina during lens wear. Further studies using retinal imaging and functional measurements during natural viewing with these lenses could confirm this potential underlying mechanism. 

Given the small sample size, the study was not able to identify baseline characteristics associated with differing axial length patterns, or in fact report on the efficacy of the novel soft contact lens design. Larger and longer-term studies are needed to further explore this new concept in modifying myopia progression in children, and to better understand tolerability and real-world wear over time.

Introduction: Most optical myopia-control strategies employ competing defocus, extended depth of focus, or light scatter to modulate ocular growth [1]. A daily disposable, single-vision soft contact lens incorporating non-refractive, light-absorbing, opaque features was developed to alter the spatiotemporal retinal luminance profile during natural eye movement without inducing defocus or blur [2]. Computational modelling [2] indicates such features generate distinct retinal ganglion cell firing patterns compared with conventional designs, and visual performance in adults was subjectively superior to a dual-focus lens [3]. In-vivo relevance for myopia control remains unknown. Experimental evidence raises concern that partial occlusion could potentiate myopiagenesis [4], underpinning the need for paediatric safety data before larger efficacy trials. This 14-month, three-phase, within-participant crossover pilot in myopic children assesses safety, feasibility, and explores axial-length signals with the proposed non-refractive lens design.

 Methods: The study was conducted at two Australian sites with independent ethics approval and trial registration. Children aged 7–15 years with myopia suitable for contact-lens wear were screened; ocular pathology and prior myopia-control therapy were exclusion criteria. Seven children enrolled; six were dispensed with lenses and completed the study (see Supplementary Fig. 1). The test lens was a daily disposable Oculfilcon D soft lens matched to the control in diameter, base curve, refractive index, oxygen permeability, centre thickness, and edge design. Both provided single-vision correction; the test lens incorporated 28 rectangular (~350 × 100 μm) opaque features within the central 5 mm optic zone [3]. At dispensing (Phase 1, 0–6 months), participants were randomised to test lens in one eye and matched control in the fellow eye; assignments crossed over in Phase 2 (6–12 months), followed by bilateral control-lens wear in Phase 3 (12–14 months). Visits occurred at 2-month intervals. The primary variable was non-cycloplegic axial length measured by non-contact optical biometry. Safety assessments included slit-lamp examination, high-contrast visual acuity (HCVA), and participant-reported comfort. Analyses is descriptive with no inferential statistics.

 Results: Baseline characteristics, HCVA, adherence, and protocol deviations are summarised in Table 1; eye-specific axial-length trajectories are plotted in Fig. 1. Slit-lamp findings were unremarkable at all visits, with no corneal infiltrative events or vision-threatening adverse events. HCVA remained stable; no participant required a change in refractive correction. Comfort was generally acceptable. Axial-length trajectories were heterogeneous: in four participants, test-assigned eyes showed attenuated axial elongation during Phase 1 relative to fellow control eyes, with directional changes after crossover in Phase 2; in the remaining two, trajectories were similar or showed no clear attenuation. No group-level treatment effect is inferred; data illustrates within-participant patterns under real-world adherence to lens-wear.