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All You Need to Know About Blue Light

By: Bollé Safety

Our modern world is flooded with artificial light. We over illuminate our homes and workplaces, bright streetlights and signage line our roads, and now the glowing screens of our mobile devices follow us everywhere we go. The development of artificial light allowed us to work longer, sleep later, and facilitates our 24hr entertainment culture.

Recent research has taken the shine off our traditional approach to lighting. Several studies have even demonstrated that blue light wavelengths emitted by most bulbs and devices can be dangerous to our health. To address this problem, we explore the new range of innovative solutions have emerged to protect us from harmful blue light in order to boost our health and productivity.

The Color of Light 
​Light is made up of electromagnetic particles that travel in waves, these waves vary in length and strength. The human eye is only sensitive to a limited part of the spectrum, what we call visible light and see as color. When visible light has longer wavelengths, and therefore lower energy, we see it as yellow, orange or red.

Whereas colors with shorter wavelengths, like violet, indigo and blue, are at the other end of the visible spectrum. The sun’s higher energy visible wavelengths collide more often with atmospheric air molecules, which is why we see the sky as blue.

Light and Circadian Rhythm
Over the course of millions of years of evolution our bodies have been tuned to the rhythms of sun. The blue-rich light of the morning sun inhibits the release of the sleep hormone melatonin. It also triggers the production of hormones like cortisol and ghrelin, which make us hungry and alert.

Whereas the red tones of the setting sun, or the growing absence of blue light, reverse the process and ready the body for sleep during the darkness of night.

This 24-hour internal clock is called the circadian rhythm, but often referred to as the body clock. As well as controlling the release of certain hormones, scientists found that it also influences fundamental bodily systems like digestion, blood pressure, temperature regulation, and metabolism.

We Are Surrounded by Blue Light

We are surrounded by blue light. It occurs naturally within sunlight and decreases as a percentage of visible light as the afternoon progresses. However, with artificial light, blue wavelengths do not decline but rather continue to illuminate the human environment long after sunset.

When photoreceptors sense the artificial blue wavelengths, the circadian system is fooled into thinking it’s the middle of the day. While ubiquitous artificial light can help us work and play whenever we want, it can be hard to avoid when we don’t want it. This is especially true in professional settings.

The Workplace Lighting
Workplaces such as offices, factories, plants and laboratories increasingly illuminate their spaces with light emitting diodes (LEDs). 

These bright and highly energy efficient bulbs support vision and address energy consumption issues. However, flooding workplaces with high energy blue LED wavelengths of light can create health problems for employees and productivity problems for bosses.

What About Our Health?

Blue light can affect our health more than most people realize. Recent studies suggest that the blue end of the light spectrum may also contribute to retinal damage and possibly lead to AMD (Age-Related Macular degeneration). The retina can be harmed by high-energy visible radiation of blue/violet light that penetrates the macular pigment found in the eye. According to a study by The Schepens Eye Institute, a low density of macular pigment may represent a risk factor for AMD by permitting greater blue light damage. High-intensity light can have a detrimental impact on our eyes, mind, and body. It is essential to be aware of the risks to be able to protect yourself.

The majority of research on the effects of blue light has centered on the mechanisms behind the damage to the photoreceptors after just a short exposure to high intensity light. Other studies claim that subthreshold exposure to blue light can also induce damage in photoreceptors.

Several experts have suggested the total amount of blue light received during our lifetime can be a significant factor in the development of age-related macular degeneration (AMD).
Several investigations have proved that exposure to light of specific wavelengths or intensity may induce severe damage to the retina, which can impact vision. Photochemical damage to the eye occurs when the eyes are exposed to light of high intensity in the bluer ranges of the visible spectrum (390–600 nm).
“The current view suggests that there are two distinct types of photochemical damage,” write Tosin et al. in a 2016 paper on blue light and eye physiology. “The first type is associated with short but intense exposure to light, and the second type is associated with longer but less intense light exposure.” Both have implications for vision and other bodily systems.

“Constant” Screen Checkers
A study by the American Psychological Association (APA) reports that 86% of adults in the US say they “constantly or often” check their emails, texts and social media accounts. These “constant checkers” as APA calls them, have higher stress levels than those who do not engage with technology as frequently.

On a 10-point scale, where 1 is “little or no stress” and 10 is “a great deal of stress,” the average reported overall stress level of constant checkers is 5.3. For non-constant checkers, the average reported stress level is 4.4. Light damage is a key reason for this stress and its knock on health effects.

Blue light exposure in the evening affects the quality of our sleep, and regular exposure may lead to sleep disorders. “Modern societies are now facing challenges in achieving adequate sleep and experiencing a multitude of sleep disturbances,” said Dr. Ana C. Krieger in an issue of Sleep Journal.

Sixty-two percent of US adults report regularly experiencing a sleep problem a few nights per week, and just over 12% have a chronic sleep disorder, according to the Statistic Brain Research Institute.

“The preliminary results show that blue-depleted LED light at night minimizes circadian disruption,” said Dr. Martin Moore-Ede, former Harvard professor and lead author of the research. It “also appears to prevent the elevated appetite and insulin resistance seen in the same subjects exposed to conventional LED lights at night,” he added.

The ​Night Shift
“If awake at night the body has reduced capacity to repair and clear oxidative DNA damage,” said Dr. Parveen Bhatti of the Fred Hutchinson Cancer Research Center in Seattle. “Over time, this accumulation would likely increase the risk of cancer across multiple sites as has been observed among shift workers,” she added.

Light exposure in the evening and night increases diabetes risk by 37% in men, according to research in Shift Work and Diabetes Mellitus by Gan Y et al. of Huazhong University of Science and Technology. Another study on night shift workers linked the effects of conventional LED lights at night with insulin resistance and diabetes risk. The paper, titled Taking the Obesity and Diabetes Risk out of Light at Night, highlights that the risks can be avoided simply by removing bio-active blue wavelengths from white LED light.

Protecting Yourself from Blue Light
Taking precautions to keep your eyes safe from blue light has multiple benefits in our daily lives. In fact, 72.6% of American adults reported in 2018 that they did not know eyewear can be used to protect the eyes from short- and long-term effects of digital eye strain. Fortunately, there are many ways to protect yourself from blue light that are highly effective with little effort required. 

Blue Light Depleted LED Lighting
Manipulation of the color emitted by LED lights is one of a number of options that have emerged to protect people against the dangers of blue light exposure.

Blue light depleted and color adaptive lighting systems can be programmed to mimic the natural patterns of the sun in indoor environments. Bluer light is emitted in the morning, which then gradually becomes redder as the day progresses.

This artificial sunlight keeps professionals tuned to nature’s rhythms, thereby minimizing the damaging impacts of excessive blue light exposure.

Blue Light Screen Filters
Blue light filters on mobile phones, computer screens and other devices are also becoming more common. In built functions such as Apple’s Night Shift and Android’s Night Mode limit the blue spectrums of light emitted by the device in the evening to reduce blue light exposure in the hours before going to sleep.

Blocking screens entirely from evening activities is even better, but this is not always possible with the demands of work and the culture of entertainment.

The 20-20-20 Rule
Taking a more pragmatic stance Dr. Beth Lennox, a doctor of optometry at Cambridge Eye Care in Ontario Canada, promotes the 20-20-20 rule. Every 20 minutes, take a 20-second break and focus your eyes on something at least 20 feet away. “This simple rule will give your eyes a much needed break and reduces eye strain and other computer related eye stress,” explains Lennox.

These solutions focus on controlling our environment and behavior to limit our exposure to blue light, however this is not always possible or desirable. Professionals may be forced into high blue light situations throughout the day or night in order to do their jobs.

Be it in front of unfiltered screens or in well-lit spaces, such exposure may have a detrimental effect on the health of those workers. Until regulation catches up with the science of light and sleep, these professionals will need to find a solution that works in every artificially lit environment.

Blue Light Blocking Glasses
Blue light blocking glasses act as a personal blue light filter, they can protect the wearer at any time and wherever they go. These glasses generally block 99% of light at wavelengths shorter than 480 nm, which makes up the vast majority of potentially harmful blue light.

A study of blue light by researchers at the University of Toronto tested this theory. Melatonin levels of people exposed to bright indoor light who were wearing blue light blocking glasses were compared to people exposed to regular dim light without wearing glasses. When both groups demonstrated similar melatonin levels it reinforced the hypothesis that blue light is a potent suppressor of sleep and that blue light blocking glasses offer viable protection.

Several authors have investigated the amount of blue light received during an individual’s entire lifespan. They propose that it can be an important factor in the development of age-related macular degeneration (AMD). According to the 2016 the paper by Tosini, et al., “the use of lenses (intra- and extraocular) that block blue light (“blue-blockers”) may provide some protection against the development of AMD.”

Last Word
The growing body of science has made it clear that exposure to artificial blue light leads to a range of serious health impacts. This is especially true for professionals working in well-lit environments and those who spend long hours in front of screens.

Thankfully, as the science of light damage has increased so has our ability to protect ourselves. It is now essential to ensure people know the dangers of blue light and have access to protective measures.

*Provided by:
Bollé Safety
2810 Caribou Court, Suite 160
Carlsbad, CA 92010

Jacqueline "Jackie" Annis is an industrial hygienist with the Office of Partnerships and Recognition, Directorate of Cooperative and State Programs in OSHA’s National Office.  Jackie’s primary responsibilities include developing and overseeing internal policies and procedures for the VPP, reviewing VPP on-site evaluation reports for process safety management information, serving as the National Office liaison for two of OSHA’s ten Regions, and facilitating the management of OSHA’s National Strategic Partnership Program.  She is an integral part of OSHA’s National Office team. 

She has served with the Agency for 36 years, including five years as a senior industrial hygienist in OSHA’s Office of Health Enforcement, Directorate of Enforcement Programs in the National Office and 17 years as a compliance safety and health officer in the Denver, CO Area Office.  Prior to her tenure at OSHA, Jackie worked as an industrial hygienist for the Department of the Navy in Alameda, California.  Jackie obtained a Bachelor of Science degree from Old Dominion University in Norfolk, VA in 1983.

Wayne Howard earned a B.S. in Chemical Engineering from UC Davis and has spent 12 years with Shell (at Martinez) refinery, 3 years with the consulting firm Process Safety, 15 years with Valero (at Benicia), and the last 10 years in the Corporate Process Safety Department. He is the Valero representative to AFPM's Advancing Process Safety Initiative.

Nathan Obaugh, PE is a senior engineer in the Safety and Operational Excellence Group at NuStar Energy. Nathan has over 10 years of PSM and process design experience in the petrochemical, refining and midstream industries. At NuStar, Nathan oversees all elements of the corporate PSM program and works directly on hazard analysis, process safety studies, PSM/RMP audits and provides process engineering support to the operations and capital projects groups.

Jared Teter, PhD is a senior staff scientist with a background in physics and hazards analysis. He has extensive experience in subscale testing of energetic materials and has served as program manager for several large testing and risk management projects. He has applied engineering and risk management protocols while evaluating the risk associated with propellant and explosives manufacturing, combustible dust, and other hazardous material related processes.

Tim Belitz has a degree in Environmental Health/Industrial Hygiene from Old Dominion University and a Master’s from Duke University. He has over 25 years of Industrial Health Safety and Environmental Experience and is a Certified Safety Professional. He has many years focused on Contractor Management and Process Safety programs.

Rob Walker graduated from Virginia Tech in Microbiology and Chemical Engineering. Rob has almost 35 years of experience working in the chemical plant and refining industry. His passion for Process Safety and Mechanical Integrity began very early in his career. Rob began with his current company, Honeywell, back in 2011.

Prasad Joshi has B.S. and M.S. Degrees in Chemical Engineering from two universities in India. Prasad has over 30 years’ experience in the business. He began with Honeywell in May 2022 as Principal Maintenance Engineer. He has worked internationally in Asia and Europe.