Blue Light: our Friend or Enemy?
It is widely known how important it is to protect the eyes from the harmful UV rays of the sun; but what about the detrimental effects of Blue Light rays? Most people nowadays spend most of their “waking” hours staring at a digital screen. Studies show that 60% of people spend more than 6 hours a day in front of a digital device.
Blue Light, another name for High Energy Visible (HEV) Light in the blue and violet parts of the light spectrum, is a particularly intense light wave emitted by many modern electronic devices — including computers, tablets, TVs and smartphones — even compact fluorescent lamps.
With the increased use of electronic devices today, the population is exposed to an increasing number of blue light sources, but 63% of adults are unaware that electronic devices emit HEV blue light.
New research shows that overexposure to blue light can contribute to vision problems such as cataracts and Age-related Macular Degeneration (AMD). While the long-term implications are now only being studied, the short-term effect of digital eye strain is affecting individuals on a daily basis.
What is Blue Light?
Blue Light is a color in the “visible spectrum of light” that the human eye can see. Light consists of electromagnetic particles traveling in waves. These waves release energy and length and power. The shorter the wavelength; the higher the energy. Each wavelength is presented in a different color and is categorized as: gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light and radio waves. These wavelengths together form the electromagnetic spectrum.
The human eye is sensitive to only one part of the electromagnetic spectrum: visible light. Visible light is that part of the electromagnetic spectrum that is seen as a color: purple, indigo, blue, green, yellow, orange and red.
Blue Light has a very short wavelength of about 380nm to 500nm, which is why it produces a large amount of energy.
Blue Light Sources
Blue Light is actually everywhere. Light from the sun travels through the atmosphere, shorter, high-energy blue wavelengths collide with air molecules causing blue light to scatter everywhere. This makes the sky look blue. In its natural form, the human body uses blue light from the sun to regulate its natural sleep and wake cycles (the circadian rhythm). Blue Light also helps to increase alertness, increase reaction time, lift moods and increase feelings of well-being.
Artificial blue light sources include electronic devices such as cell phones and laptops, as well as energy-efficient fluorescent light bulbs and LED lights.
The evolution in digital display technology has progressed dramatically over the years, with many of today’s electronic devices using LED backlight technology to improve screen brightness and clarity. LEDs emit very strong blue light waves. Mobile phones, computers, tablets and flat-screen TVs are just a few of the devices that use this technology. Due to their widespread use and increased popularity, we are gradually being exposed to an increasing number of blue light sources.
Effects of Blue Light on The Human Body
Blue Light waves are among the shortest, highest-energy wavelengths of the visible light spectrum. Because they are shorter, these “blue” or High Energy Visible (HEV) wavelengths flicker more easily than longer, weaker wavelengths. This type of flicker creates a glow that can reduce visual contrast and affect sharpness and clarity.
Flashing and radiance can be one of the causes of eye strain, headaches, physical and mental fatigue caused by many hours in front of a computer screen or other electronic devices.
Natural eye filters do not provide sufficient protection against Blue Light rays from the sun, Blue Light emanating from electronic devices or Blue Light emitted by fluorescent light tubes. Prolonged exposure to Blue Light can cause retinal damage and contribute to age-related macular degeneration, which can lead to vision loss.
Blue Light can help lift moods and heighten awareness, but chronic exposure to Blue Light at night can reduce the production of melatonin, a hormone that regulates sleep, disrupting the circadian rhythm.
Harvard researchers have linked night shift and exposure to blue light at night to several types of diabetes, cancer (breast, prostate), heart disease, obesity and an increased risk of depression.
Researchers are not sure exactly why exposure to blue light at night has such adverse effects on the human body and health, but exposure to light suppresses melatonin secretion and lower melatonin levels may explain the association with these types of health problems.
Digital Asthenopia
Most people spend most of their waking hours in front of a digital screen, whether it is a computer at work, a personal cell phone, playing video games or just relaxing and watching television. Digital Asthenopia is a new term used to describe the conditions that arise from the use of today’s popular electronic gadgets.
Digital Asthenopia is a medical problem with serious symptoms that can affect learning and productivity. Symptoms of digital damage to the eyes or computer vision syndrome include blurred vision, difficulty focusing, dry and irritated eyes, headaches, neck and back pain.
Macular Degeneration
There is increasing medical evidence that exposure to Blue Light can cause permanent eye damage. Blue Light causes cell destruction in the center of the retina and plays a large role in causing age-related macular degeneration, which can lead to vision loss.
Melanin is a substance found in skin, hair and eyes that absorbs harmful UV and blue light rays. It is a natural sunscreen. Higher amounts of melanin provide greater protection, but with aging, we lose melanin, and by age 65, half of the protection disappears, causing susceptibility to eye diseases, such as macular degeneration.
Blue Light and Children
Digital Asthenopia of the eyes not only affects adults. Children are also at risk of eye damage due to their increasing use of digital devices. Kids nowadays have more digital tools than ever before — computers, tablets, smartphones, e-readers, video games … According to a study by Kaiser Family Foundation, children and teens (ages 8 to 18) spend more than 7 hours a day using electronic media. Before the age of ten, children’s eyes are not fully developed. The crystal lens and cornea are still mostly translucent and overexposed, so too much exposure to Blue Light will adversely affect the development and health of the eyes.
Vision protection
The use of goggles plays an important role in protecting the eyes from the effects of Blue Light. Sunglasses, which are especially colored or polarized to absorb the blue rays of HEVs, are used when outdoors during the day. For the interior, in low light or at night, protective coated ophthalmic lenses are available, designed to reflect and cut high energy Blue Light. Thanks to the coatings of blue light, the harmful part of the Blue Light stops while a good part of the Blue Light passes away.
In order to minimize the harmful effects of Blue Light, it is also necessary to adjust the screen light to the current environment, keep the screens clean, position the screens at or slightly below eye level, increase the font size, use the 20–20–20 method (every 20 minutes. 20 seconds to look at the subject 20 feet away), blink more often, take breaks, limit screen time, reduce the use of electronic devices toward the end of the day.
Conclusion
Although Blue Light is a natural phenomenon, present throughout the day and beneficial to the human body, it is different from the Blue Light emitted by electronic devices. At the moment, artificial Blue Light does not cause more serious problems, only discomfort, while in the long run it can pose a major problem for the human body.
In order to maintain eye health and enhance human life in the digital world, the optical industry is investing in new lens and eyewear technologies that will minimize eye strain and the penetration of harmful Blue Light. Many technology industries also place filters on the screens of various electronic devices, thus extending the “safe” time of use of the device.
Due to today’s “digital” lifestyle, in which a person is surrounded by blue light throughout the day (and night), the harmful effects of Blue Light cannot be stopped completely, but only mitigated by preventative measures.
