Myopia, or nearsightedness, affects some 3 billion people worldwide. That number is increasing, and the fuzzy vision issue is affecting kids as young as 6 and 7 years old.
In fact, the World Health Organization predicts 5 billion people — half the world's population — will be nearsighted by 2050. Beyond just needing glasses or contacts, high myopia increases the risk of other vision problems down the road, such as retinal detachment, glaucoma and macular degeneration.
A study published Tuesday in Cell Reports Medicine by researchers at Cincinnati Children's and the University of Alabama at Birmingham (UAB), suggests better indoor lighting may help prevent myopia.
Specifically, the study looked at the effects of indigo light, a short-wavelength light, in tree shrews. The squirrel-like animals have eyes that are very similar to human eyes.
"We found that if you include these indigo light wavelengths in the normal lighting in which the tree shrews live, you can prevent them from getting myopia even when you try to induce it," corresponding author Richard Lang, PhD, director of research in the Division of Ophthalmology at Cincinnati Children’s, tells WVXU.
"You can cause a tree shrew to get myopia, but if you have indigo light present, you can prevent it, even though you are attempting to produce it. That is a pretty good indication that in the human population you'll see the same thing."
Myopia occurs when the optical axis of the eye from front to back is too long. Images, then, get focused on the front of the retina rather than the retina itself, making them fuzzy instead of clear.
"Indigo light — for the aficionados, this is 430 nanometers — it's this deep blue color, but it turns out that that little slice of the spectrum is crucial to prevent the eye from going through this process where it grows too long," says Lang.
There's plenty of indigo light in sunlight to help your eyes grow to the appropriate length, but it's lacking in indoor lighting. Lang says one immediate solution to reduce myopia risk is to make sure kids spend at least two hours outdoors every day.
"The longer-term solution may be to develop this lighting technology so that it can be in everybody's house," he says.
Of course, Lang explains, myopia occurs from a variety of factors, including using electronic devices and close-in work that changes the way the eye responds to optic stimuli.
Typical indoor lighting such as white LEDs emit substantial, longer-wavelength light, which supports vision, but doesn't appear to stimulate the light-sensitive pathways needed to 'see the whole picture,' as it were. In other words, we need the full spectrum of light the sun provides for normal eye development.
Cincinnati Children's already uses — and is studying — full-spectrum lighting in its neonatal intensive care unit (NICU). In a regular setting, the lighting looks normal, but the indigo light is also "on."
Lang and his co-author from UAB, Rafael Grytz, PhD, want to see if adding indigo light to indoor lighting will have the same results as it did with the tree shrews.
"The goal is to install our lighting in a series of daycare centers because the kids are the right age, and obviously we can probably do the most good there," Lang says.
They would then monitor children in those centers over time to see whether myopia development is reduced compared to daycares with standard lighting.
Why daycares?
"What we see worldwide is that the incidence of myopia has increased a lot, and you see it earlier in kids, and so the way this works typically is that you start to see myopia appearing in children who are 6 and 7 years old, and so the idea is that if you want to perform an intervention, you have to do so before that age," Lang says.
The researchers are seeking funding for that now.
Finding that funding, however, has been a challenge. He estimates they need at least $2 million. Normally, that's something researchers would request a grant for from the National Institutes for Health (NIH). Their grant requests, he says, haven't been successful, so they're turning to private foundations to seek funds.
Thousands of NIH grants have been terminated since a January 2025 executive order from President Donald Trump. Since then, NPR reports the institutes have awarded fewer grants than in the past, and there have been other funding disruptions for research.
While the lighting technology exists for commercial settings, such light bulbs for use in homes do not. The researchers note there are a variety of specialty lamps marketed to help with circadian rhythms, but lighting with the necessary characteristics to prevent myopia aren't widely available.
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