"Previous experiments in mice had indicated that violet light near 380 nanometers could reduce myopia. Those studies also showed that opsin 5 (OPN5), a light-sensing receptor, was necessary for the protective effect. However, light at that wavelength did not produce the same response in tree shrews. Their eye lenses, like human lenses, block most wavelengths below roughly 400 nanometers. "Human lenses, and now we know tree shrew lenses, don't transmit a lot of light in the ultra-violet spectrum," Lang says. "They basically cut off most wavelengths below 400 nanometers. This finding pushed us to explore slightly longer wavelengths that could still stimulate OPN5. Ultimately, we found that indigo light from 419 to 446 nanometers was the most effective at preventing myopia." That result led the researchers toward indigo light, which is capable of passing through the lens while still activating the biological pathway they were investigating." #science #vision https://www.sciencedaily.com/releases/2026/08/260824065510.htm