Researchers have identified a narrow band of blue-violet light that prevented experimentally induced myopia in tree shrews, raising the possibility that the lighting used inside homes, schools and childcare facilities could influence how children’s eyes develop. The study, led by scientists at Cincinnati Children’s and the University of Alabama at Birmingham, found that exposure to indigo light with wavelengths between 419 and 446 nanometers completely suppressed the development of nearsightedness in a tree shrew model. The findings, published online August 18, 2026, in Cell Reports Medicine, offer a new explanation for why myopia has become increasingly common as children spend more time indoors under artificial lighting.
Myopia, commonly called near-sightedness, occurs when the eye grows too long from front to back. Light entering the eye is then focused in front of the retina rather than directly on its surface, causing distant objects to appear blurred. The condition usually begins during childhood and can worsen throughout adolescence. Although glasses and contact lenses can correct the refractive error, severe myopia is associated with a higher lifetime risk of retinal detachment, glaucoma, myopic macular degeneration and other sight-threatening complications. Epidemiological models have estimated that almost half of the global population could be myopic by 2050, making the search for preventable environmental factors an urgent public-health priority.
Outdoor exposure has long been linked to lower rates of childhood myopia. Children who spend more time outdoors tend to be less likely to become near-sighted, even when other factors such as close work and family history are considered. Bright outdoor environments provide a complex mixture of wavelengths that is difficult to reproduce indoors, while daylight also encourages the eyes to focus across a broad range of distances. The new study focuses on a less obvious difference between outdoor and indoor environments: the spectral composition of light. Although modern white LEDs appear bright to human vision, their output does not reproduce the full balance of wavelengths found in sunlight and contains relatively little indigo light.
To investigate whether this missing portion of the spectrum could affect eye growth, the researchers used tree shrews, small mammals whose eyes share important anatomical and optical characteristics with human eyes. The animals can develop a strong, predictable form of experimental myopia when one eye is fitted with a tiny spectacle lens that alters the visual signal reaching the retina. The untreated eye provides an internal comparison, allowing researchers to track how the abnormal visual input changes the growing eye. During the experiments, the team exposed the animals to different wavelengths of light and monitored their eyes with a biometer, which measures axial length, and an autorefractor, which measures changes in refractive power.
Axial elongation is a central biological feature of progressive myopia. As the eye lengthens, the retina is displaced farther from the optical focus, producing increasingly blurred distance vision. The tree shrews exposed to indigo light did not show the expected increase in axial length despite receiving a powerful myopia-inducing visual signal. According to the researchers, the effect was most pronounced within the 419-to-446-nanometer range. The result suggests that specific wavelengths may activate regulatory pathways that restrain the remodeling of the sclera, the tough outer layer of the eye, or otherwise alter signals controlling ocular growth.
The investigation builds on earlier experiments in mice, which indicated that violet light near 380 nanometers could suppress myopia. Those studies implicated opsin 5, or OPN5, a light-sensitive receptor involved in non-image-forming visual pathways. OPN5 is distinct from the photopigments primarily responsible for color vision and can respond to light in ways that influence biological processes beyond the formation of visual images. However, light below approximately 400 nanometers falls in the ultraviolet range and is largely blocked by the lenses of both humans and tree shrews. The Cincinnati Children’s and UAB team therefore tested slightly longer wavelengths capable of reaching the retina and potentially stimulating the same receptor system.
The researchers interpret the findings as evidence that indoor lighting may be one modifiable contributor to the worldwide rise in myopia. Standard white LED lamps are commonly engineered to produce a strong peak around 450 nanometers, helping create a visually pleasant white appearance when combined with other wavelengths. Yet the overall spectral profile can differ substantially from sunlight, particularly in the short-wavelength region around indigo. The scientists propose that the developing eye may respond not only to the brightness of an environment but also to its detailed spectral composition. If children regularly spend their formative years under lighting that lacks signals present in daylight, the balance of biochemical pathways involved in refractive development could potentially be altered.
The study does not mean that ordinary indoor lighting has been proven to cause myopia, nor does it establish that indigo lamps will prevent the condition in children. The experiments involved animals, controlled exposure conditions and a deliberately strong model of abnormal eye growth. Human myopia is influenced by a complex combination of genetics, education, near work, outdoor time, visual behavior and other environmental factors. The authors also disclose potential financial interests: Richard Lang and Rafael Grytz are listed as inventors on pending patents for lighting devices related to the research, and Grytz is a founder and chief science officer of Electric Indigo, a UAB startup in which the university holds an ownership interest. These factors make independent replication and carefully designed clinical trials especially important.
The next stage will move the idea from laboratory animals toward real-world lighting environments. Researchers at Cincinnati Children’s Science of Light Center are exploring whether daycare facilities can be equipped with lighting systems enriched in the relevant indigo wavelengths. Children would then be monitored over time and compared with those attending facilities using conventional lighting, with assessments likely to include refractive error, axial length and patterns of outdoor exposure. Such a trial would need to determine the appropriate intensity, duration and timing of indigo exposure while evaluating potential effects on sleep, circadian biology, visual comfort and retinal health. If the findings are confirmed, biologically informed lighting could become a passive complement to established strategies such as increasing outdoor activity—not a replacement for them—and could offer schools, hospitals and homes a scalable way to make indoor environments more similar to the daylight conditions under which human vision evolved.
Subject of Research: Animals; tree shrews and experimental myopia
Article Title: Prevention of myopia in a near-primate by supplemental indigo light suggests a hypothesis for the myopia boom
News Publication Date: 18-Aug-2026
Web References: https://doi.org/10.1016/j.xcrm.2026.102999; https://www.cincinnatichildrens.org/bio/l/richard-lang; https://www.uab.edu/medicine/ophthalmology/faculty/grytz; https://www.cincinnatichildrens.org/research/divisions/s/science-of-light
References: Cell Reports Medicine, DOI: 10.1016/j.xcrm.2026.102999
Image Credits: Cincinnati Children’s
Keywords: myopia, near-sightedness, indigo light, blue-violet light, LED lighting, eye development, tree shrews, OPN5, axial elongation, childhood vision, ophthalmology, preventive medicine
