What is blue light?

　　The sunlight of nature consists of red, orange, yellow, green, cyan, blue and purple. The light of each color has different energies and wavelengths. Red light has longer wavelengths and less energy. On the other hand, blue light has a shorter wavelength and more energy. The biggest source of blue light is sunlight. In addition, there are many other sources: LED lights, flat panel LED TVs, computer monitors, smartphones and tablets.

　　Almost all visible blue light passes through the cornea and lens to the retina. Blue light can affect vision and can cause premature eye aging. A study by the American Academy of Optometry found that working on a laptop for only two hours can cause eye pain and vision problems. A typical office worker spends at least eight hours a day on a computer screen or on a smartphone. How do we protect our eyes from the blue light from the screen?

　　1. Clean the screen and make sure that no other light is shining on the screen; try not to use the smart device in direct sunlight.

　　2. Try to sit farther away from the computer screen. The screen should not be tilted and should be directly below the line of sight.

　　3. Every 20 minutes of work, give yourself 20 seconds to rest and see where you are from a distance.

　　4. If your eyes are dry, blink more.

　　5. Drink plenty of water. One of the most important eye problems when using a computer screen is dry eyes. Dry eyes may be caused by excessive computer use, but it may also be dehydration.

　　6. Purchase a computer anti-blue film that reduces glare, increases contrast, and blocks blue light from the sun and digital screens.