Indigo Wavelength Missing from LEDs May Halt Childhood Myopia, Study Finds

Scientists at Cincinnati Children's Hospital Medical Center and the University of Alabama at Birmingham reported that supplemental indigo light— a short-wave band present in sunlight but scarce in typical white LEDs— fully blocked the onset of myopia in tree shrews, an animal model with eye characteristics similar to humans. The experiments measured eye length and refraction, showing that wavelengths between 419 and 446 nanometers activate the OPN5 photoreceptor pathway, which earlier mouse work linked to reduced nearsightedness.

Researchers argue that modern indoor environments deprive developing eyes of this crucial spectrum, contributing to the projected rise of myopia worldwide. They suggest two strategies: increasing outdoor time for children or redesigning indoor lighting to include indigo wavelengths, noting that Cincinnati Children’s NICU already uses a programmable full-spectrum system. The next phase will involve installing indigo-rich lighting in selected daycares to monitor long-term effects. The study was funded by numerous NIH grants, the Japan Agency for Medical Research and Development, and several private foundations, with co-authors also holding patents and a startup, Electric Indigo.