According to the American Optometric Association’s (AOA) 2016 American Eye-Q® survey, the average American spends 7 or more hours per day looking at an assortment of screens: phones, tablets, computers, and flat-screen televisions. For Millennials, the figure was even higher: an average of 9 hours per day. Use of these devices has only increased—and this trend will likely continue. So how is all that screen time affecting our eyes?
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The short answer is negatively. Digital device screens emit high concentrations of blue light—high-energy visible light—that can lead to an assortment of symptoms. The month of March is Save Your Vision Month, and the AOA is encouraging people to learn how blue light can affect their vision and how to keep their eyes healthy.
Blue Light Blues
Many sources of artificial light, including fluorescent bulbs and LEDs and the screens of many electronic devices, are skewed toward the high-energy, blue end of the visible spectrum.
Acute overexposure to blue light can disrupt levels of the hormone melatonin, making it harder to fall asleep and reducing the amount of time spent in REM sleep. It can also cause digital eye strain (sometimes called computer vision syndrome). Symptoms of digital eye strain include:
- Dry eyes
- Eye irritation (burning and stinging)
- Sleep problems
- Blurred vision
- Headaches
- Neck and shoulder pain
Chronic overexposure to blue light can cause permanent damage to the retina and is believed to contribute to the development of age-related macular degeneration, which is the most common cause of blindness in individuals over the age of 55.
Clear-Eyed Screen Use
In order to protect their eyes, people should monitor their digital screen usage at home and work. These steps can help to prevent eyestrain, sleep problems, and other issues:
- Go dark. As the sun goes down, dim the screens on your devices. Use lower-wattage bulbs in your bedroom, and use dimmer switches to reduce light levels at night. Turn digital devices off at least 1 hour before bed to reduce the impact of blue light on melatonin.
- Follow the 20-20-20 rule. For every 20 minutes you spend looking at a device or computer screen, take a 20-second break and focus on something that is 20 feet away. Timer programs are available that will prompt you when it’s time to take a break.
- Keep your distance. Rather than bringing the screen closer to your eyes to see small print and details, use the “zoom” feature on your device.
- Decrease glare. Reduce the amount of glare on screens by positioning screens so that they are indirectly rather than directly lit, by adjusting the device settings, or by using a glare filter to decrease the amount of blue light reflected from the screen.
- Use a filter. Software filters are also available that can reduce the amount of blue light coming from your screen. Some tablets now come with preinstalled blue light filters that can be scheduled to change the spectrum of the screen lighting at specific times of day.
- Get yourself some cheap sunglasses. While they’re not exactly cheap—a good pair costs around $80—yellow glasses that block blue wavelengths are available. And wearing regular sunglasses outdoors, even on cloudy days, can reduce your exposure to the blue portion of natural light.