Efficacy of different lighting schemes on refractive development and choroidal thickness in school-age children

To investigate the associations of a one-year intermittent, high-illuminance crystal pure full-spectrum lighting scheme on refractive development, axial length growth, and choroidal thickness in school-aged children (6-10 years), and to assess the persistence of these associations after withdrawal.

A total of 198 primary school students are randomly assigned into an experimental group (n = 102) receiving high-illuminance crystal pure full-spectrum lighting and a control group (n = 96) receiving conventional LED lighting. The intervention involves 4 h of daily exposure during school hours for one year. Axial length, axial curvature ratio, and macular choroidal thickness are measured bilaterally at five time points.

The experimental group demonstrates a significantly smaller increase in axial length and a more pronounced increase in choroidal thickness compared to the control group. The axial curvature ratio improves significantly in the experimental group (3.02 ± 0.07) versus the control group (p < 0.001). Refractive changes show clear improvement post-intervention and maintain a regular pattern afterward. Furthermore, changes in choroidal vascular index are significantly higher in the experimental group during both autumn (1.38 ± 0.79%) and spring (1.52 ± 0.86%) intervention periods (p < 0.001). The density of choriocapillaris flow deficit also decreases significantly in the experimental group (13.11 ± 3.80%) compared to controls.

Intermittent high-illuminance crystal pure full-spectrum lighting was associated with choroidal thickening and slower axial elongation in children, offering a promising, evidence-based strategy for myopia prevention and control within school environments.