United States researchers have found that indigo light, which is found in sunlight but not in standard indoor lighting, prevented myopia in tree shrews, a mammal that has a human-like visual system.1
The researchers said the findings may explain why outside time reduces myopia risk.
Vision researchers from the Cincinnati Children’s Hospital and several universities focused their study on indigo light – a short-wavelength light that is abundant in sunlight but poorly represented in standard white LED lighting.
In their experiments the team demonstrated that exposure to indigo light completely prevented induced myopia from developing in the tree shrews.
If these hypotheses are confirmed in humans, spectral modifications to built environments could contribute to reducing the growing burden of myopia
“Several testable predictions with translational implications emerge from this study,” the authors wrote.
The first is that increasing daytime outdoor exposure is supported as a strategy to reduce myopia; that indoor lighting spectra in the specific indigo band should be evaluated as a practical myopia prevention strategy in children; and that because ‘blue blocking’ spectacles reduce indigo light transmission, widespread daytime use in children could “plausibly increase the risk of myopia”.
“If these hypotheses are confirmed in humans, spectral modifications to built environments could contribute to reducing the growing burden of myopia,” they concluded.
Reference
- Grytz R, El Hamdaoui M, Lang RA, et al. Prevention of myopia in a near-primate by supplemental indigo light suggests a hypothesis for the myopia boom. Cell Rep Med. 2026;102999. doi: 10.1016/j.xcrm.2026.102999.