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. But when it comes to protecting your vision and keeping your eyes healthy, blue light isn’t your biggest concern.

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.

If being outside on a sunny afternoon likely doesn’t damage the human retina, then neither can your dim-by-comparison tablet. A theoretical study recently reached the same conclusion.