• Digital Devices and Your Eyes

    Reviewed By Ninel Z Gregori MD
    Dec. 10, 2020

    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 reports about studies on blue light. These studies use cells in a dish and animals to study the effects of blue light. These studies showed that blue light can cause cell damage in these settings. But these experiments did not:

    • mimic the natural conditions of blue light exposure to live human eyes
    • use blue light from computer screens

    So far, the evidence shows no meaningful link between blue light and: