Blue light has gotten a bad rap, getting blamed for loss of sleep and eye damage. Personal electronic devices emit more blue light than any other color. Blue light has a short wavelength, which means that it is high-energy and can damage the delicate tissues of the eye. It can also pass through the eye to the retina, the collection of neurons that converts light into the signals that are the foundation of sight.
Laboratory studies have shown that prolonged exposure to high-intensity blue light damages retinal cells in mice. But epidemiological studies on real people tell a different story.
As an assistant professor at The Ohio State University College of Optometry, I teach and conduct vision research, including work with retinal eye cells. I also see patients in the college’s teaching clinics. Often, my patients want to know how they can keep their eyes healthy despite looking at a computer screen all day. They often ask about “blue-blocking” spectacle lenses that they see advertised on the internet.
One way to think about blue light and potential retinal damage is to consider the sun. Sunlight is mostly blue light. On a sunny afternoon, it’s nearly 100,000 times brighter than your computer screen. Yet few human studies have found any link between sunlight exposure and the development of age-related macular degeneration, a retinal disease that leads to loss of central vision.