But what about the harmful effects of blue light rays?
How many hours do you spend in front of a digital screen? Most of us spend the majority of our waking hours staring at a digital screen. Studies suggest that 60% of people spend more than 6 hours a day in front of a digital device.
What is blue light?
Light is made up of electromagnetic particles that travel in waves. These waves emit energy, and range in length and strength. The shorter the wavelength; the higher the energy. The length of the waves is measured in nanometers (nm), with 1 nanometer equaling 1 billionth of a meter. Every wavelength is represented by a different color, and is grouped into the following categories: gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light, and radio waves. Together these wavelengths make up the electromagnetic spectrum. However, the human eye is sensitive to only one part of this spectrum: visible light. Visible light is that part of the electromagnetic spectrum that is seen as colors: violet, indigo, blue, green, yellow, orange and red. Blue light has a very short wavelength, and so produces a higher amount of energy. Studies suggest that, over time, exposure to the blue end of the light spectrum could cause serious long-term damage to your eyes.
Where is blue light found?
Blue light is actually everywhere. When outside, light from the sun travels through the atmosphere. The shorter, high energy blue wavelengths collide with the air molecules causing blue light to scatter everywhere. This is what makes the sky look blue. In its natural form, your body uses blue light from the sun to regulate your natural sleep and wake cycles. This is known as your circadian rhythm. Blue light also helps boost alertness, heighten reaction times, elevate moods, and increase the feeling of well being. Artificial sources of blue light include electronic devices such as cell phones and laptop computers, as well as energy-efficient fluorescent bulbs and LED lights. Sources of blue light include the sun, digital screens (TVs, computers, laptops, smart phones and tablets), electronic devices, and fluorescent and LED lighting.
Why should we be concerned about blue light exposure?
Blue light waves are the among the shortest, highest energy wavelengths in the visible light spectrum. Because they are shorter, these "Blue" or High Energy Visible (HEV) wavelengths flicker more easily than longer, weaker wavelengths. This kind of flickering creates a glare that can reduce visual contrast and affect sharpness and clarity. This flickering and glaring may be one of the reasons for eyestrain, headaches, physical and mental fatigue caused by many hours sitting in front of a computer screen or other electronic device. Our eyes' natural filters do not provide sufficient protection against blue light rays from the sun, let alone the blue light emanating from these devices or from blue light emitted from fluorescent-light tubes. Prolonged exposure to blue light may cause retinal damage and contribute to age-related macular degeneration, which can lead to loss of vision.
Where is the increased exposure to blue light coming from? The evolution in digital screen technology has advanced dramatically over the years, and many of today's electronic devices use LED back-light technology to help enhance screen brightness and clarity. These LEDs emit very strong blue light waves. Cell phones, computers, tablets and flat-screen televisions are just among a few of the devices that use this technology. Because of their wide-spread use and increasing popularity, we are gradually being exposed to more and more sources of blue light and for longer periods of time. Spending just two consecutive hours on a digital device can cause eyestrain and fatigue.
Blue Light and Digital Eyestrain
Most of us spend the majority of our waking hours staring at digital screen, whether it's the computer at work, our personal cell phone, playing a video game, or just relaxing and watching TV. Digital eyestrain is a new term used to describe the conditions resulting from the use of today's popular electronic gadgets. Digital eyestrain is a medical issue with serious symptoms that can affect learning and work productivity. Symptoms of digital eyestrain, or computer vision syndrome, include blurry vision, difficulty focusing, dry and irritated eyes, headaches, neck and back pain. Digital eyestrain has overtaken carpal-tunnel syndrome as the number one computer-related complaint. Digital eyestrain does not just affect adults. Children are also at risk for eyestrain due to their growing use of digital devices. Children today have more digital tools at their disposal than ever before – tablets, smart phones, e-readers, video games are just among a few.
According to a study by the Kaiser family Foundation, children and teenagers (ages 8-18) spend more than 7 hours a day consuming electronic media. Before age 10, children's eyes are not fully developed. The crystalline lens and cornea are still largely transparent and overexposed to light, so too much exposure to blue light is not a good thing. Parents should supervise and limit the amount of screen time their children are permitted. Be sure to see your eye doctor at least every two years for a comprehensive eye examination. It is a good way to monitor your eye health, maintain good vision and keep track of your solar radiation protection needs as well as new advances in eye protection.