Prevention of myopia in a near-primate by supplemental indigo light suggests a hypothesis for the myopia boom.

Today, about 2.8 billion people worldwide suffer from myopia (nearsightedness), and projections place the 2050 burden at 4.8 billion people (the "myopia boom"). Myopia results from abnormal elongation of the eye, which causes images to focus in front of the retina. Building on prior work in mouse models assessing the non-visual opsin OPN5, we test the hypothesis that insufficient exposure to short-wavelength light increases myopia susceptibility. We use the tree shrew, a near-primate model for human myopia. Our findings show that indigo light in the range of 419-446 nm, when used to supplement a warm white light-emitting diode (LED), completely suppresses myopia induced by minus-lens wear. A large body of genetic and epidemiological evidence suggests that the "myopia boom" has an environmental cause. Our findings align with this evidence and suggest that one contributing factor is the relative absence of indigo light in built environments where we spend 86% of our time.