Don’t read or watch TV in the dark. Don’t sit so close to the screen. If you watch too much you’ll ruin your eyesight. That’s what mom and dad always said.

The good news is they were right, but perhaps not for the reason you think. The blue light emitted from digital devices can cause sleep disruption, long-term vision issues, retinal damage, and other health concerns.

You could say mom and dad were visionaries (no pun intended). Their advice is even more relevant today with 87% of adults spending more than two hours a day on digital devices. We use them for just about everything from gaming, photos, video, texting, and even as an alarm clock. Many of us use two or more at the same time.

Digital screens are a major source of blue light, second only to the sun

Blue light is at the edge of the visible light spectrum, right next to ultraviolet or UV light. It has the shortest wavelengths and highest energy. It’s vital to the growth and development of our eyes and vision. And, it plays a primary role in regulating circadian rhythms (our bodies’ natural wake/sleep cycle). Exposure to it can stimulate alertness, cognitive function, and elevate mood.

But blue light has a dark side

Because of the shorter wavelength, blue light waves tend to flicker more, which causes glare and contributes to digital eyestrain. In fact, 31 percent of computer users suffer from eye strain. More than 22 percent experience dry eyes, headache, and blurred vison.

Waves from blue light can penetrate all the way to the back of the eye. New research shows a connection between exposure to blue light and long-term damage to the retina. This is thought to contribute to vision loss from conditions such as age-related macular degeneration.

What you can to do control blue light exposure

  • Don’t sit so close to the screen – Keep the display at least arm’s length away. Choose the correct device for a task:
    • Smartphones for brief text messages or talking.
    • Tablets, e-readers, or computers for reading .
    • Computers with a full size keyboard for emailing and word processing.
  • Don’t use your device in the dark – Constant exposure to blue light disrupts normal wake/sleep patterns.
  • Don’t watch so much – Limit the amount of time spent in front of digital screens. When that’s not possible, follow the 20-20-20 rule to give your eyes frequent breaks.

Accessories can help

  • Screen filters or an app for digital devices that reduce the amount of blue light.
  • Eyewear with special computer lenses block blue light and reduce eyestrain.
  • Lenses with anti-reflective properties reduce glare and block blue light waves from all sources.

Blue light has become so relevant it is the focal point of the American Optometric Association’s Save Your Vision Month.

So heed your mother’s advice and follow these steps to keep your eyes healthy and save your vision.