Digital Devices and Your Eyes
Digital devices are everywhere today. With computers, tablets, and smartphones fixtures of our lives at home, work and school, we spend more time with screens than ever before.
News reports about blue light, computer eye strain and “digital detox” offer varied recommendations for screen use, so it’s helpful to know what the science tells us about safe screen exposure for children and adults.
What is blue light?
Color doesn’t typically come to mind when thinking of light, but when you see a rainbow, you are seeing the visual light spectrum. These are colors visible to the human eye and include red, blue, green “wavelengths.” All light we see is a combination of these wavelengths, including light from the sun and computer screens.
Blue light and sleep
Exposure to blue light from the sun as well as our screens boosts mood and alertness—a sunrise signals to our brain that it’s time to wake up. But too much exposure to blue light from screens in the evening can disrupt our body’s natural sleep cycle, known as the circadian rhythm. Light slows the production of melatonin—the sleep hormone—in our body. For more restful sleep, be sure to:
- set devices to night or dark mode in the evening. This setting lowers screen brightness and its warm colors are less likely to confuse your body into thinking it’s daytime.
- avoid using screens one to two hours before going to sleep.
Can blue light damage your eyes?
You may have heard the news reports about a study on blue light. It looked at how blue light affects retinal, a natural form of vitamin A, which is found in the eye.
The study showed that retinal—when exposed to blue light—can cause cell damage. But the experiments in the study did not:
- mimic the natural conditions of blue light exposure to live eyes
- use cells derived from retina cells
- use blue light from computer screens
While the study may prove helpful for other reasons, it didn’t show that blue light from screens harms vision.