Restoring a Missing Slice of Sunshine to Indoor Light May Help Prevent Myopia

By studying near-sightedness in tree shrews, experts at Cincinnati Children's and UAB report a potential method for protecting the vision of hundreds of millions of children

Key Takeaways

• Researchers found that indigo light, a wavelength abundant in sunlight but rare in standard indoor lighting, prevented myopia in a tree shrew model with human-like vision.
• The findings suggest indoor lighting may be one modifiable factor contributing to rising rates of childhood near-sightedness worldwide.
• Next steps include testing indigo-enriched lighting in daycare settings to learn whether it can reduce myopia risk.

CINCINNATI, Aug. 18, 2026 /PRNewswire/ -- Research has already shown that the more time children spend playing with screens indoors instead of playing outdoors, the more likely they are to develop myopia. In fact, some experts predict that nearly 5 billion people (or 50% of the world population) will be near-sighted by the year 2050.

Now, a new study led by vision researchers at Cincinnati Children's and the University of Alabama at Birmingham suggests that myopia can be prevented through improved indoor lighting. Details were published online Aug. 18, 2026, in Cell Reports Medicine.

The research focuses on indigo light— a short-wavelength light that is abundant in sunlight but poorly represented in standard white LED lighting. In experiments involving tree shrews—an animal model that has a human-like visual system—the team demonstrated that exposure to indigo light completely prevents nearsightedness from developing.

"The model of myopia we use in the tree shrew is fairly extreme," says corresponding author Richard Lang, PhD, director of research in the Division of Ophthalmology at Cincinnati Children's. "So, if indigo light can suppress myopia in these tests, then it should also be quite effective in humans."

What is myopia?

Myopia, or near-sightedness, develops when the eye grows too long from front to back. This prevents images from focusing directly on the retina in the back of the eye, causing distant objects to appear blurry.

Myopia usually begins in childhood and can progress through adolescence. Beyond the need for glasses or contact lenses, high myopia increases the risk of vision-threatening complications later in life, including retinal detachment, glaucoma and macular degeneration.

Why tree shrews?

The study used tree shrews because their eyes share anatomical and optical features with human eyes.

The study's first author, Rafael Grytz, PhD, a visual sciences expert with the University of Alabama Birmingham (UAB), uses a method to fit tree shrews with tiny spectacles that create a strong myopia-inducing signal in one eye while allowing the other eye to serve as a comparison.

"Even though tree shrews look like squirrels, they are a near-primate, with an eye very similar to that of humans, and so are a good model to study the cause of myopia in the human population," Grytz says.

The team used these animals in a series of tests that exposed them to different wavelengths of light while using a biometer to measure the axial length of the eye and an autorefractor to measure refractive changes over time.

Earlier work in mice suggested that violet light near 380 nanometers could suppress myopia and revealed that opsin 5 (OPN5), a light-sensing receptor, was required for this response. But that wavelength did not work in tree shrews because, as in humans, the ocular lens blocks most light below about 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."

A compensation for indoor culture?

The findings support a broader idea that modern indoor life has changed the lighting environment in ways that affect children's eye development. Standard white LEDs typically have a peak around 450 nanometers and emit substantial longer-wavelength light that supports vision. But they provide little of the indigo light that appears to stimulate non-visual opsins—light-sensitive pathways involved in biological processes beyond image formation.

"We evolved outside in the full-spectrum light provided by our sun," Lang says. "When we live inside, we don't get all the wavelengths the eye needs for normal refractive development, and so we get myopia. That's the basic message of this paper."

One way to prevent myopia would be to encourage children to spend much more time outside, where their eyes can focus between a wider range of near and distant objects while their growing bodies are bathed in full-spectrum sunlight. But reversing the course of our increasingly technical culture appears unlikely.

Another way to prevent myopia would be to improve lighting systems. In 2021, based on previous studies showing how light exposure influences eye development, Cincinnati Children's became the first pediatric hospital to install a programmable, full-spectrum lighting system in its neonatal intensive care unit (NICU). Research on the impact of the new lighting system continues.

Currently, a variety of specialty lamps have been marketed to help offset disruptions to natural circadian rhythms, such as travelers becoming exhausted by jetlag. However, lighting products with the relevant characteristics that could prevent myopia are not widely available.

Next step: testing lighting designs with children

The Science of Light Center at Cincinnati Children's is exploring how lighting design can influence child health in various ways. While the tree shrew data is powerful, the team still needs to test whether indigo-enriched lighting actually prevents myopia in children.

The next phase for this research will involve installing improved lighting in participating daycare spaces. Then the team would monitor children over time to see whether myopia development is reduced compared to daycare facilities that use standard lighting.

Lang says the long-term aim is not simply to make indoor lights brighter, but to make them biologically more complete—closer to the range of wavelengths humans evolved with outdoors.

"What's our best option? It is to change the lighting environment inside," Lang says. "If future clinical studies confirm the findings, indigo-enriched lighting could become a safe, passive and scalable way to help reduce childhood myopia risk."

About the study

This study was carried out as a collaboration between the research teams of Richard Lang at Cincinnati Children's and Rafael Grytz at UAB with important contributions from Takahiro Yamashita at Kyoto University and Mehlika Inanici at The University of Washington.

Several organizations provided grants to fund this research, including the National Eye Institute of the National Institutes of Health (EY026588, EY036560, EY032633, EY003039, EY038143, EY028666, EY032029, EY032752, EY032566, and EY034456); the National Institute of General Medical Science (GM152641); the Japan Agency for Medical Research and Development (22gm1510007); the EyeSight Foundation of Alabama, Research to Prevent Blindness, the Henry M. Hollis Fund, the Emma and Irving Goldman Scholar Endowed Chair and the Cincinnati Children's Hospital Research Foundation.

Grytz and Lang declare they are inventors listed on pending patents for lighting devices related to this work. Grytz also is founder and CSO of Electric Indigo, a UAB startup in which UAB holds an ownership interest.

SOURCE Cincinnati Children's Hospital Medical Center