Study finds indigo light suppresses myopia in tree shrews

A new study published in Cell Reports Medicine has suggested that reduced levels of indigo light in built environments may be fuelling the global increase in myopia levels.

The researchers highlighted that experiments in tree shrews found indigo light in combination with a warm light light-emitting diode suppressed myopia.

The scientists determined that the most protective wavelength is 419–446 nanometres (nm).

However, the study authors highlighted that there is a relative scarcity of this wavelength within built environments.

“A large body of genetic and epidemiological evidence suggests that the ‘myopia boom’ has an environmental cause,” the scientists noted.

“Our findings align with this evidence and suggest that one contributing factor is the relative absence of indigo light in built environments where we spend 86% of our time,” they added

The researchers highlighted that an “abundance” of 419–446 nm photons in sunlight may explain why outdoor time reduces myopia risk.

Creating indoor environments that incorporate indigo lighting may be investigated as a practical myopia prevention strategy in children, the study authors suggested.

The researchers added that the use of blue-blocking spectacles in children could plausibly increase the risk of myopia – as these spectacles reduce indigo light transmission to the eyes.

“If these hypotheses are confirmed in humans, spectral modifications to built environments could contribute to reducing the growing burden of myopia,” the scientists shared.

Lead author, Professor Rafael Grytz, from the University of Alabama at Birmingham, has established a startup, Electric Indigo, that is aiming to develop light-emitting eyewear to prevent the development of myopia.

In 2025, the company received a $357,000 (£264,000) grant from the National Eye Institute in the US to support the development of the technology.

Main image: a prototype of the eyewear in development by Electric Indigo.