Violet light transmission through eyeglasses and its effects on myopic children: A systematic review and...

Myopia is a refractive error that impairs visual function and leads to visual blurring. This study aims to investigate the effect of violet light (VL) on controlling myopia, specifically in terms of axial length (AL), spherical equivalent refraction (SER), and visual acuity (VA).

A systematic review was conducted to compare VL and single-vision spectacles (SVSs) for treating childhood myopia. The search terms used were "Myopia" and "Violet Light." Extensive searches were carried out in the PubMed, Embase, and Cochrane databases. The mean differences were evaluated. The effects of the therapy were examined. Publication bias was assessed with a funnel plot and further investigated through sensitivity analysis. Meta-analysis was performed using Bayesian statistics with Jeffery's Amazing Statistical Package.

The meta-analysis included 126 myopic children: 64 in the VL group and 62 in the SVS group. The pooled effect size for AL shortening was evaluated as 0.659 ± 0.184, with a 95% credible interval of 0.299-1.023. The pooled effect size for SER decrease was estimated as 0.669 ± 0.188, with a 95% credible interval of 0.303-1.036. Likewise, for VA in Log-MAR, after intervention (VL and SVS), the values were 0.082 ± 0.171 with a credible interval of 0.262-0.423. Publication bias was assessed with a funnel plot, which revealed no bias. Impact sizes for the fixed effect model were determined due to the similarity in study population, geography, type of intervention, and study design.

VL transmission glasses play a significant role in controlling myopia among children, resulting in axial shortening, reduction of SER, and improvement in VA. However, further investigation is required to examine the long-term rebound effect.