Effects of Myopia Control Spectacle Lenses on Peripheral Refraction and Contrast: Insights From Optical Modeling

Purpose: To investigate potential optical cues underlying myopia control effects by examining how lenslet-array spectacle lenses influence peripheral refraction and image contrast. Methods: Three commercial lenslet-array spectacle lenses-MiyoSmart, Stellest, and diverse segmented defocus optics-were reconstructed in Zemax OpticStudio, together with a conventional single vision (SV) lens as a reference. The reconstructed lenses were coupled with the Navarro eye model to simulate spectacle wearing after experimental validation of the lens models. Optical performance was evaluated under both distance and near viewing conditions with accommodative lags of 0.50 diopters (D) and 1.00 D. Peripheral refraction components (M and J0) were derived from wavefront data. Point spread functions and modulation transfer functions were obtained, with the area under the modulation transfer function curve subsequently calculated. Results: Simulated and experimental point spread functions showed strong agreement, confirming the reliability of the constructed spectacle models. Compared with the SV lens, the lenslet-array introduced M fluctuations (within ±0.25 D), manifesting as alternating positive and negative shifts relative to the SV baseline. Only the Stellest lens exhibited minimal myopic defocus over a limited eccentricity range, while the other designs failed to induce peripheral myopic defocus. In the horizontal meridian between 12.5° and 17.5° eccentricity, lenslet-array lenses exhibited reduced contrast at low spatial frequencies (≤6 cycles/degree) but increased cutoff frequencies and relatively enhanced contrast at higher frequencies (9-15 cycles/degree). Similar patterns were observed under near viewing with a 0.50 D accommodative lag. Conclusions: The myopia control efficacy of lenslet-array lenses may not be fully explained by the peripheral myopic defocus hypothesis. Instead, the observed reduction in low spatial frequency contrast, coupled with an elevated cutoff frequency that preserves high-frequency information, may provide the critical optical cues for slowing myopia progression. These hypothesized mechanisms warrant further clinical investigation.