A systematic review and meta-analysis of 12 randomized controlled trials investigated the effect of repeated low red light (RLRL) on refractive development in children over 12 months. RLRL treatment significantly slowed the progression of myopia as shown by improvements in axial eye length (AL) and spherical equivalent refractive error (SER) compared to controls at 1, 3, 6, and 12 months. The effect on AL and SER was most pronounced within 3 months, after which it began to decrease. Conversely, no evidence was found for an effect of RLRL on anterior corneal curvature. The meta-analysis shows a non-linear trend in the effectiveness of RLRL, with its effect gradually decreasing after three months of treatment. The results suggest that RLRL may be an effective non-invasive method to slow refractive progression in children, but its effect on the cornea remains unclear. The study was registered under the identifier CRD42024575823.