Restoring a missing slice of sunshine to indoor light may help prevent myopia

Myopia, or nearsightedness, 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.

Research has already shown that the more time children spend playing with screens indoors instead of outdoors, the more likely they are to develop myopia. In fact, some experts predict that nearly 5 billion people (or 50% of the world's population) will be nearsighted by 2050.
Now, a new study led by vision researchers suggests that myopia can be prevented with 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 with a human-like visual system—the team demonstrated that exposure to indigo light completely prevented nearsightedness from developing.
The study used tree shrews because their eyes share anatomical and optical features with human eyes.

Researchers used these animals in a series of tests that exposed them to different wavelengths of light while using a biometer to measure eye shape and axial length 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 ultraviolet spectrum.
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 nonvisual opsins—light-sensitive pathways involved in biological processes beyond image formation.
We evolved outside in the full-spectrum light provided by our sun. 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 research paper.
One way to prevent myopia would be to encourage children to spend much more time outside, where their eyes can focus across 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.

Prevention of myopia in a near-primate by supplemental indigo light suggests a hypothesis for the myopia boom, Cell Reports Medicine (2026). DOI: 10.1016/j.xcrm.2026.102999. www.cell.com/cell-reports-medi … 2666-3791(26)00416-7