- Myopia (nearsightedness) currently affects around 2.8 billion people worldwide. Cases are expected to rise to 4.8 billion by 2050, an increase known as “myopia boom.”
- A recent study found that indigo light could completely suppress lens-induced myopia in tree shrews.
- Researchers suggest that supplementing indoor lighting with indigo light in schools may help prevent myopia, although human studies are needed to prove safety and efficacy.
There are currently around 2.8 billion people worldwide with myopia, also known as nearsightedness or shortsightedness. By 2050, the number of cases will rise to around 4.8 billion. Some people refer to this as the “myopia boom.”
This is according to information from a study published in
The researchers note that evidence suggests environmental factors may play a role in the “myopia boom,” and that there is a relative absence of indigo light in built environments, where people spend around 86% of their time.
In particular, the researchers focused on a model classroom environment, as myopia often first appears in childhood. According to the American Optometric Association (AOA), it typically develops in school-aged children, although it can also begin in adulthood.
According to the study findings, indigo light could help suppress myopia, though more, particularly human-based, research is necessary.
Indigo light helped suppress lens-induced myopia in tree shrews
The study researchers used tree shrews as a model for human myopia as they are diurnal mammals — animals that are awake during daylight and asleep during nighttime — and closely related to primates.
They placed spectacles on the tree shrews when they were 24 days old, an age when they are most susceptible to myopia. One lens acted as a control, and the other lens induced myopia in one eye.
The tree shrews were then exposed to different wavelengths of supplemental light.
The researchers ultimately determined that indigo light in the range of 419 to 446 nanometers (nm), which supplemented a warm white LED, completely suppressed minus-lens-induced myopia.
Study author Rafael Grytz, PhD, Dennis Endowed Professor of Glaucoma Research at the University of Alabama at Birmingham Department of Ophthalmology and Visual Sciences, spoke with Medical News Today about these findings.
“A large body of genetic and epidemiological evidence suggests that the epidemic rise of myopia also called 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 children spend more and more of their time compared to previous generations.”
Can the study’s findings help with preventing myopia in childhood?
As the study was conducted in tree shrews, it is not possible to say from the findings whether supplemental light can help prevent myopia in childhood.
The researchers did create a computer model of a classroom and simulated visual wavelengths and μ-opic illumination — a measurement of light — at the eyes of a seated child.
The results of the test determined that, while warm white LEDs can provide good brightness, combining them with indigo light could better support eye health in indoor locations and potentially prevent or reduce the risk of myopia.
However, as this was a simulation, additional tests in real-world settings would need to be conducted.
Grytz also explained that “
