Artificial Blue Light: Negative / Positive Health Effects

The Good, the Bad and the Ugly Effects of the Blue Light

Artificial Blue Light: Negative / Positive Health Effects

They are your best friends. You spend time with them almost regularly. You are in a myth! The freaking truth is they are your enemies.

Enough of suspense, Wanna know whom we are talking about?

They are your favourite digital devices whom you are hooked to all the time.

Day or night, millennials and even the Gen Z are connected with digital devices, especially smartphones. It’s good to use but bad to get addicted and it’s even ugly if you get affected by its negative health effects. When we stare at our smartphones or computer screens, the high density blue light is ly to attack the eyes.

Blue light is actually good, in fact, even the natural sunlight emits blue light but as we all know anything in excess is injurious. You obviously do not keep on staring at the sun as you stare at the digital devices and that is when blue light turns out to be really harmful for your eye health.

Blue light is quite close to ultraviolet light on the light spectrum, so it is usually believed that it is equally harmful as ultraviolet. It is not really true but due to prolonged exposure to digital screens, it turns out to be more dangerous than the UV.

The good blue light exposure from the sun

Sun is natural and the biggest source of blue light. UV is indeed harmful but the sun’s blue light during the day is really good for humans.

It makes the person more active, more attentive in work and also positively affects the brain. And in fact, due to fresh, energetic and active daytime, you are assured with a good night sleep.

Only thing is you need to switch off all the artificial sources of blue light before sleeping.

The bad blue light exposure from digital devices

The artificial source of blue light, digital devices are bad, bad and only bad, especially for your eyes. Your eyes are not meant to filter the light and hence it fails to protect the eyes.

The artificial blue light emitted from digital devices smartphones, laptops, computers, tablets lead to an unhealthy lifestyle. It affects the natural functioning of the brain and also causes sleep deprivation.

If you have a habit of working or playing games late at night, you are kind of confusing the brain. Due to the artificial source of light, the brain assumes it’s day which eventually hampers the sleep pattern.

The ugly side of blue light

Your eyes are constantly glued to the digital screens get badly affected by the dangerous blue light. Retinal damage, Computer Vision Syndrome (digital eye strain), blurred vision are common vision problems caused due to the blue light. It also increases the chances of the age related macular degeneration which in the worst case scenario can make a person go blind.

One thing is for sure, living without digital devices is impractical, so it’s wise to go for digital eye protection options blue light blocking glasses that will shield your eyes from the harmful light. Anti-reflective lens coating can also reduce the amount of blue light from entering your eyes and also eliminate the screen glare. You can consult your doctor what best suits your vision needs


Blue Light: What is it, How Does it Affect Your Health, and What Can You do to Limit Harmful Exposure?

Artificial Blue Light: Negative / Positive Health Effects

In the last 20 years, advances in technology have dramatically improved the efficiency of our lighting options, from bulbs to mobile phones to computer screens.

Ever since humans figured out the whole fire thing, we’ve been advancing at the pace of our ability to create useful artificial light.

Here’s a quick rundown of the last 5,000 years of light, if you’re just tuning in this century: [1]

  • 5,000 years ago: Candles invented, being awake after dark surges in popularity.
  • 240 years ago: The first fixed oil lamps make interior lighting way better, and safer too.
  • 150 years ago: Thomas Edison, and other electrical engineers, have the first “light bulb” moments, resulting in a pretty famous invention.
  • 100 years ago: Electricity becomes the norm in the industrialized world, and the first light-emitting diodes (LEDs) are invented.
  • 30 years ago: NASA funds the first clinical studies of red light-emitting LEDs for biological uses.
  • 15 years ago: Shuji Nakamura invents blue LEDs, the latest major lighting innovation.

Not all light is created equal. Blue light is one of the highest energy and most efficient wavelengths within the light spectrum. Harnessing it for everyday lighting has been such a big advance that Shuji Nakamura won the 2014 Nobel Physics Prize for pioneering it. Blue light can have a lot of health benefits for humans, but in this case, too much of a good thing becomes a bad thing.

This article will give you a quick overview of blue light: what it is, how it works, pros, cons, and the best ways to limit the darker side of modern blue light advances.

What’s Blue Light?

red light, blue light is part of the visible light spectrum, where it ranges between approximately 380nm & 500nm, making it one of the shortest, highest-energy wavelengths. In natural sunlight, blue light is always present with red light, leading to numerous therapeutic effects.

Blue light isn’t just in sunlight though; it’s everywhere, including the screen you’re reading this on right now. In fact, TVs, computers, and cell phones use mostly blue light for their screens.

Because of its efficiency and low cost, blue light has also become the dominant wavelength for everyday home and commercial lighting.

Fun fact: 95% of the energy from blue wavelengths is converted to light, leaving only 5% wasted as heat. [2]

Blue light isn’t all good news though. Increasingly, better LED technology has allowed us to remove the red and near infrared (NIR) wavelengths from many of our primary light sources. This increases efficiency because of a higher concentration of blue wavelengths. For energy use and savings, this is a classic win-win scenario. But our bodies, and our sleep, may be the unexpected losers.

In natural sunlight, blue wavelengths are always together with red wavelengths, so our bodies, long ago, evolved to metabolize the two together. But when blue is present without red, in most of our modern environments, there are possible negative ramifications. Next, we'll break down both the potential positive and negative health effects of excess blue light.

Blue Light and Your Health: PROs

If you’re trying to make the most efficient light bulb or computer screen, you want as much blue light as possible. But when it comes to your health, remember, blue always goes better with red.

The blue light you get from natural sunlight can be good for you because it comes with the full light spectrum, including therapeutic red and near infrared light.

Natural blue light is especially important for regulating your vital circadian rhythm, the term for your body’s asleep-awake cycle.

To explain, let’s jump to your brain. The suprachiasmatic nucleus (SCN) is a little part of your hypothalamus that acts as the body’s master alarm clock.

[3] The SCN controls your sleep cycle, and when it gets a healthy dose of blue and red light during daylight hours, you sleep better. You’re also more alert, and have better hormone levels, body temperature, immune function, and digestion.

[3] If you stay inside too much and don’t get enough natural light during the day, odds are your sleep isn’t as well regulated and you’re more tired than you should be.

Blue Light and Your Health: CONs

With all due respect to Eiffel 65 and their 1999 hit single Blue (Da Ba Dee), too much blue light is bad for your health.

It’s great during the day when your body expects it, and helps your brain communicate effectively to the rest of your body.

But now we live in a blue-lit world where our electronics and home lighting hit us with blue light at all hours. Our bodies just weren’t designed for round-the-clock blue light.

Getting blue light at dark times of the day messes with our body’s natural cycles. That’s why watching TV, or scrolling on your phone right before bed, can make it harder to sleep.

Your body is getting all that blue light and the color is essentially telling your brain it’s the middle of the day, right before you try to shut down for the night.

Your SCN doesn’t know, or care, that you have to wake up early for work tomorrow, it’s partying it’s noon when you stare at a bright screen in the dark before bed. [3]

In addition, we're learning more about how melatonin is the hormone responsible for regulating the sleep/wake cycles in the brain. Not surprising, blue light directly inhibits our body’s melatonin flow, hurting our ability to fall asleep, in addition to negatively impacting the quality of the sleep we get.

[4,5] Poor sleep over time can become a chronic condition, and exhaustion can make it much harder to overcome other health challenges. There are so many people who don’t get enough sleep and feel the negative consequences every day.

Most of these folks have no idea that the artificial blue light they’re surrounded by all the time is one of the biggest hurdles to restful sleep.

What Can You Do About Harmful Blue Light Exposure?

Feeling blue from poor sleep and lack of energy? Here are some practical ways you can cut back on your artificial blue light exposure and improve your body’s natural rhythms.

  • Block Blue: Find some blue light-blocking eyewear and software for your devices that limits your blue exposure. [6]
  • Add Red: Lower color temperature lighting amber and red wavelengths are good choices after dark. The Joovv is an ideal alternative for nighttime lighting.
  • Go Darker at Night: After the sun sets, keep your surroundings darker so your body can wind down before bed. Reading real print is better than a screen. Blackout window coverings and sleep masks work for many people because they block out unwanted light at night.
  • Catch the Sunrise: Romantic sunsets get all the love, but a great way to reset your circadian rhythm is to get up early and watch the sun come up. [7]

Conclusion: Red > Blue When it Comes to Health

Blue light has done amazing things for our lighting and electronics, but our bodies and sleep cycles pay the price when we overload with artificial blue wavelengths at the wrong times.

While natural blue and red light from the sun have numerous health benefits when absorbed together, blue light by itself is keeping us up at night and causing those bags under our eyes in the morning.

The good news is you can easily cut back on artificial blue light and add more healthy, red light to your life, especially with something a full-body Joovv.

Scientific Sources and Medical References:

[1] Timeline of Lighting Technology, Wikipedia

[2] The Advantages of LED Lights for the Environment, Sepco

[3] Moore, R. “Suprachiasmatic nucleus in sleep-wake regulation” Sleep Med. 2007, Dec 8 Suppl, 3:27-33.

[4] Gooley, J., Chamberlain, K., Smith, K., Khalsa, S., et al. “Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans” J Clin Endocrinol Metab. 2011, Mar; 96(3): E463–E472. doi: 10.1210/jc.2010-2098

[5] Brown, RL & Robinson, PR. “Melanopsin: shedding light on the elusive circadian photopigment” Chronobiol Int. 2004 Mar; 21(2):189-204.

[6] Burkhart K & Phelps JR. “Amber lenses to block blue light and improve sleep: a randomized trial” Chronobiol Int.


Is blue light from your cell phone, TV bad for your health?

Artificial Blue Light: Negative / Positive Health Effects

From televisions and smartphones to tablets and gaming systems, most of us are glued to our electronic devices. But is all of that blue light shining from screens harmful to our health? Melissa Barnett, principal optometrist at the UC Davis Eye Center, talks about the effects of blue light and what you can do to reduce the health risk.  

Using electronic devices at night without adjusting the amount of blue light that shines from the screen can affect sleep.

What is blue light?

Blue light is part of the visible light spectrum — what the human eye can see. Vibrating within the 380 to 500 nanometer range, it has the shortest wavelength and highest energy.

About one-third of all visible light is considered high-energy visible, or “blue,” light. Sunlight is the most significant source of blue light.

Artificial sources of blue light include fluorescent light, compact fluorescent light (CFL) bulbs, LEDs, flat screen LED televisions, computer monitors, smart phones and tablet screens.

What are the health benefits of blue light? 

Blue light boosts alertness, helps memory and cognitive function, and elevates mood. It regulates the circadian rhythm, the body's natural wake and sleep cycle. Sunlight is also important for the growth and development of the eyes and vision in children. Inadequate exposure to blue light can also contribute to the recent increase in myopia, or nearsightedness.

Is too much exposure to blue light unhealthy?

Blue-light exposure from screens is small compared to the amount of exposure from the sun. However, there is concern about the long-term effects of screen exposure especially with excessive screen time and when a screen is too close to the eyes.

How is blue light bad for health?

Since the eye is not good at blocking blue light, nearly all visible blue light passes through the front of the eye (cornea and lens) and reaches the retina, the cells that convert light for the brain to process into images.

Continued exposure to blue light over time could damage retinal cells and cause vision problems such as age-related macular degeneration.

It can also contribute to cataracts, eye cancer and growths on the clear covering over the white part of the eye.

According to a study funded by the National Eye Institute, children are more vulnerable than adults because their eyes absorb more blue light from digital devices.

Exposure to blue light before bedtime also can disrupt sleep patterns because it affects when our bodies create melatonin.

Does blue light contribute to digital eye strain?

Yes. Short-wavelength, high-energy blue light scatters more easily than other visible light. Because computer screens and digital devices emit a lot of blue light, this unfocused visual “noise” reduces contrast and can contribute to digital eye strain.

People also tend to blink less when using digital devices, which contributes to dry eye and eye strain. Other common signs of eye strain include headaches, blurred vision, and neck and shoulder pain. According to the Vision Council, 27% to 35% of Americans reported experiencing one of these symptoms after using digital devices.

What do blue-light glasses do?

While there are many studies on blue light glasses, there isn’t consensus. They can help protect eyes from eye strain caused by overexposure to blue light. The glasses can also help people fall asleep, stay asleep and have a more restful sleep.

Theoretically, commercially available blue light-filtering lenses reduce negative effects by 10.6% to 23.6% without reducing quality. Lenses that block blue light with wavelengths less than 450 nm (blue-violet light) also help by significantly increasing contrast.

As a result, computer glasses with yellow-tinted lenses may increase comfort when viewing digital devices for long periods of time.

Do I need blue light glasses?

If you spend a lot of time using digital devices and notice digital eye strain, blue light glasses may be helpful.

According to the Vision Council, 80% of American adults use digital devices more than two hours per day.

Nearly 67% use two or more devices at the same time, and 59% experience symptoms of digital eye strain. Blue light glasses also may be helpful if you have trouble falling asleep.

How can I reduce the negative effects of blue light?

  • Get blue-light filters for your smartphone, tablet and computer screens. The filters prevent much of blue light from these devices from reaching the eyes without affecting the visibility of the display. 
  • Follow the 20-20-20 rule to reduce digital eye strain. Take a 20-second break to view something 20 feet away every 20 minutes.
  • Control lighting and glare on the device screen, set up a good working distance and posture for screen viewing. Be sure that even minor vision problems are properly corrected.
  • Talk with your eye doctor about blue light protection and digital device use at your next eye examination.


Blue light has a dark side

Artificial Blue Light: Negative / Positive Health Effects

Although it is environmentally friendly, blue light can affect your sleep and potentially cause disease. Until the advent of artificial lighting, the sun was the major source of lighting, and people spent their evenings in (relative) darkness. Now, in much of the world, evenings are illuminated, and we take our easy access to all those lumens pretty much for granted.

But we may be paying a price for basking in all that light. At night, light throws the body's biological clock—the circadian rhythm— whack. Sleep suffers. Worse, research shows that it may contribute to the causation of cancer, diabetes, heart disease, and obesity.

Light and sleep

Everyone has slightly different circadian rhythms, but the average length is 24 and one-quarter hours. The circadian rhythm of people who stay up late is slightly longer, while the rhythms of earlier birds fall short of 24 hours. Dr. Charles Czeisler of Harvard Medical School showed, in 1981, that daylight keeps a person's internal clock aligned with the environment.

Is nighttime light exposure bad?

Some studies suggest a link between exposure to light at night, such as working the night shift, to some types of cancer, diabetes, heart disease, and obesity.

That's not proof that nighttime light exposure causes these conditions; nor is it clear why it could be bad for us.

But we do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there's some experimental evidence (it's very preliminary) that lower melatonin levels might explain the association with cancer.

A Harvard study shed a little bit of light on the possible connection to diabetes and possibly obesity. The researchers put 10 people on a schedule that gradually shifted the timing of their circadian rhythms. Their blood sugar levels increased, throwing them into a prediabetic state, and levels of leptin, a hormone that leaves people feeling full after a meal, went down.

Even dim light can interfere with a person's circadian rhythm and melatonin secretion.

A mere eight lux—a level of brightness exceeded by most table lamps and about twice that of a night light—has an effect, notes Stephen Lockley, a Harvard sleep researcher.

Light at night is part of the reason so many people don't get enough sleep, says Lockley, and researchers have linked short sleep to increased risk for depression, as well as diabetes and cardiovascular problems.

Effects of blue light and sleep

While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.

5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs.

1.5 hours).

In another study of blue light, researchers at the University of Toronto compared the melatonin levels of people exposed to bright indoor light who were wearing blue-light–blocking goggles to people exposed to regular dim light without wearing goggles.

The fact that the levels of the hormone were about the same in the two groups strengthens the hypothesis that blue light is a potent suppressor of melatonin. It also suggests that shift workers and night owls could perhaps protect themselves if they wore eyewear that blocks blue light.

Inexpensive sunglasses with orange-tinted lenses block blue light, but they also block other colors, so they're not suitable for use indoors at night. Glasses that block out only blue light can cost up to $80.

LED blue light exposure

If blue light does have adverse health effects, then environmental concerns, and the quest for energy-efficient lighting, could be at odds with personal health. Those curlicue compact fluorescent lightbulbs and LED lights are much more energy-efficient than the old-fashioned incandescent lightbulbs we grew up with. But they also tend to produce more blue light.

The physics of fluorescent lights can't be changed, but coatings inside the bulbs can be so they produce a warmer, less blue light.

LED lights are more efficient than fluorescent lights, but they also produce a fair amount of light in the blue spectrum.

Richard Hansler, a light researcher at John Carroll University in Cleveland, notes that ordinary incandescent lights also produce some blue light, although less than most fluorescent lightbulbs.

Protect yourself from blue light at night

  • Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin.
  • Avoid looking at bright screens beginning two to three hours before bed.
  • If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength at night.
  • Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.

image: © Innovatedcaptures |

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Blue Light Exposed

Artificial Blue Light: Negative / Positive Health Effects

We all know how important it is to protect our eyes from the sun's harmful UV rays; but what about the harmful effects of blue light rays?

We all know how important it is to protect our eyes from the sun's harmful UV rays; 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.

Blue light is a colour in the “visible light
spectrum” that can be seen by the human eye. 

Blue light is a colour in the “visible light
spectrum” that can be seen by the human eye. 

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 colour, 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 colours: 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.

Wavelengths are measured in nanometers (nm).  1 nanometer equals 1 billionth of a meter.
AMD: age-related macular degeneration

Blue light is actually everywhere.When outside, light from the sun travels

through the atmosphere. 

Blue light is actually everywhere.When outside, light from the sun travels

through the atmosphere. 

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.

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.

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.

Sources of blue light include the sun, digital screens (TVs, computers, laptops, smart phones and tablets), electronic devices, and fluorescent and LED lighting.

Most of us spend the majority of our waking hours staring at a digital screen. Blue light has been known to cause flickering and glaring.

Most of us spend the majority of our waking hours staring at a digital screen. Blue light has been known to cause flickering and glaring.

Strain is often caused by the distance between the eyes and a digital screen.

Blue light can help elevate your mood and boost awareness, but chronic exposure to blue light at night can lower the production of melatonin, the hormone that regulates sleep, and disrupt your circadian rhythm. 

Harvard researchers have linked working the night shift and exposure to blue light at night to several types of cancer (breast, prostate) diabetes, heart disease, obesity and an increased risk for depression.

Researchers aren't exactly sure why exposure to blue light at night seems to have such detrimental effects on our health, but it is known that exposure to light suppresses the secretion of melatonin and lower melatonin levels might explain the association with these types of health problems.

In two American surveys of children aged 12 to 15 years released in July 2014, researchers at the U.S. Centers for Disease Control and Prevention found that nearly three-quarters spent at least two hours a day watching TV and using a computer.

The surveys also found that 15 percent of teens watch four or more hours of TV daily, while nearly 12 percent report using their computers for four or more hours a day. The surveys didn't ask teens about their use of smartphones.

Dr. Marjorie Hogan, a pediatrician who helped write the American Academy of Pediatrics guidelines on kids' screen time, recognizes parents have a tough task limiting TV and computers for kids in that 12 to 15 age range – especially in the age of social media.

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, videogames 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.

Nearly 70% of adults who report regular usage of media devices experienced some symptoms of digital eyestrain, but many did nothing to lessen their discomfort mainly due to lack of knowledge.

93% of teens have a computer or have access to one.

There's growing medical evidence that blue light exposure may cause permanent eye damage; contribute to the destruction of the cells in the center of the retina; and play a role in causing age-related macular degeneration, which can lead to vision loss.

Melanin is the substance in the skin, hair, and eyes that absorbs harmful UV and blue light rays. It's the body's natural sunscreen protection.  Higher amounts of melanin afford greater protection, but as we age we lose melanin, so that by age 65 half of the protection is gone making us more susceptible to eye disease such as macular degeneration.

The retina is a very thin, multi-layered tissue covering the inner eyeball. The retina can be harmed by high-energy visible radiation of blue/violet light that penetrates the macular pigment found in the eye. A low macular pigment density may represent a risk factor for age-related macular degeneration by permitting greater blue light damage to the retina.

A Harvard medical study states that “High Energy Visible (HEV) blue light has been identified for years as the most dangerous light for the retina.

 After chronic exposure, one can expect to see long range growth in the number of macular degenerations, glaucomas, and retinal degenerative diseases”.

  And a paper published by the American Macular Degeneration Foundation (AMDF) reports that “the blue rays of the spectrum seem to accelerate age-related macular degeneration (AMD) more than any other rays in the spectrum”.

Who needs protection from blue light exposure?

We all do. Everyone needs to take precautions against the effects of blue light.  Whether we work in an office or play in the sun; spend hours staring at a computer screen or texting on our cell phones, we are all being exposed to blue light.


Is Blue Light Bad For Your Health?

Artificial Blue Light: Negative / Positive Health Effects

From the WebMD Archives

June 19, 2017 — Peek into the typical American household after dinner and you’ll find the occupants bathed in a faint bluish glow.

As parents fire off late emails on their laptops or lie in bed with eyes fixed on e-readers, kids update their Snapchat accounts or squeeze in one last game on their phones.

Even if the gadgets are off, new eco-friendly street lamps, TVs, and household bulbs shine into the night, emitting a brighter, shorter-wavelength (more bluish), and more potent light than older incandescent bulbs did.

All that concerns Charles Czeisler, PhD, MD, chief of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital in Boston.

“The more research we do, the more evidence we have that excess artificial light at night can have a profound, deleterious effect on many aspects of human health,” says Czeisler, who is also director of sleep medicine at Harvard Medical School. “It is a growing public health concern.”

Czeisler is among a growing number of physicians, researchers, and health policy makers sounding the alarm that dark nights — a healthy diet, regular exercise, and good sleep habits — are a key, endangered ingredient for long-term health.

Last year, the U.S. National Toxicology Program convened a 2-day workshop to explore mounting research linking exposure to artificial light at night not just to sleep problems, but also to weight gain, depression, cancer, and heart disease.

In October, NASA went so far as to change all the lights on the International Space Station to ones that, as night falls, dim and change to longer-wavelength light, which has been shown to have less impact on human physiology than “blue light.

Last June, the American Medical Association chimed in. It issued a statement showing concerns that the new ultra-bright light-emitting diode (LED) lamps many cities are now using in their streetlights could “contribute to the risk of chronic disease.”

Much of the research so far has been done on animals or comes from large population studies, which show patterns but don’t confirm cause and effect. But many health experts say the results are troublesome enough to warrant action now.

“As opposed to the many other kinds of harmful environmental pollutants out there, we are rapidly figuring out exactly what to do about this one, and it is really not that hard,” says Richard Stevens, PhD, a University of Connecticut cancer epidemiologist and light-at-night researcher. Just dim the lights at night and tone down that blue, he says.

Light is by far the most important synchronizer of human circadian rhythms, or body clocks, Czeisler says.

Specialized cells in the retina are finely tuned to respond to the short-wavelength light that comes from a cloudless blue sky.

As light rays hit those cells, they tell the brain to stop pumping out drowsiness-inducing melatonin and start making hormones cortisol and ghrelin that wake us up and make us hungry.

At dusk, in an electricity-free world, the opposite happens. As light fades, the body begins to transition to “nighttime physiology,” in which melatonin levels rise, body temperature drops, sleepiness grows, and hunger goes away.

The time spent in this restful state, even if we are not actually sleeping, is restorative, Stevens says.

Trouble is, in the modern world, we are bathed by lights that have the same potent wavelength that wakes up to, so our transition to nighttime physiology has been delayed by hours.

As Stevens puts it, we are “darkness deprived.”

The best-documented consequence, by far, of excess evening light exposure is short-term sleep disruption. In one study, people in a sleep lab who read from an e-reader at night saw their nighttime melatonin levels drop by 55% after 5 days, took longer to fall asleep, had less restorative rapid eye movement (REM) sleep, and felt more groggy the next day than those reading a paper book.

Another study, looking at teenagers, suggests they may be even more sensitive to light at night. Just an hour of exposure from a glowing device, a phone, suppressed melatonin by 23%; 2 hours decreased it by 38%.

Sleep issues aside, light at night is now being accused of helping fuel weight gain and metabolic diseases. Studies show that people exposed to more bright light at night are hungrier and produce less insulin, making it harder for them to turn those late-night snacks into fuel. As a result, it rests in the blood, where it makes diabetes more ly, or it's stored as fat.

One March 2016 study by University of Haifa researchers compared World Health Organization obesity data with military satellite images of nighttime lighting and found that the men and women who lived in the places most illuminated at night were also the most ly to be obese.

Animal studies at Ohio State University show that even exposure to relatively dim light — about the brightness of a child’s nightlight 3 feet from the eyes — over 8 weeks has a measurable impact on the brain. It raises inflammation and lowers levels of a hormone that's key for promoting new brain cell growth. It also causes transmitters between neurons to whither.

The animals also showed “depressive symptoms” and had memory problems, says study author Randy Nelson, chairman of the department of neuroscience at Ohio State University.

While studies looking at the way light at night affects the human brain are only in their infancy, population studies of emergency room workers and oilfield workers chronically exposed to bright light at night show similar thinking and mood impairments, even if those workers are getting enough sleep, Nelson says.

“This is not just a sleep problem. This is a problem of disruption of the entire circadian clock, and sleep is just one hand of that clock.”

Research is young, but some studies suggest that chronic exposure to excess light at night may also fuel cancer, in part by lowering the levels of melatonin — a known anti-cancer agent — circulating in the blood. Female night shift workers have a 50% to 70% greater chance of developing breast cancer during their lifetime, says David Blask, MD, associate director of the Tulane University Center for Circadian Biology.

One recent study of 75,000 nurses, published in the American Journal of Preventive Medicine, found that those who worked the night shift for more than 5 years were 11% more ly to die early. Some European governments, with health risks in mind, now pay women night shift workers hazard pay.

“In a sense, with all our gadgets, we are all night shift workers to a degree now,” says Blask.

Mariana Figueiro, PhD, light and health program director at the Lighting Research Center in Troy, NY, stresses that in addition to minimizing bright blue-hued light — especially from gadgets held close to the eyes — at night, we should try to maximize the amount of bright light we get during the day.

“It not only makes you more awake and alert by day; research suggests it may also make you less sensitive to the negative health consequences of light at night,” she says.

Stevens says that beyond the 7 to 8 hours of sleep you try to get each night, you should make an effort to get 3 more hours of relative darkness.

You don't need to live by candlelight after dinner, but it’s a good idea to dim the lights and steer clear of bright blue screens.

Replace the lights in your bedroom and bathroom with dimmer, longer-wavelength lights, consider using blackout shades if streetlights shine into your window, and invest in an eye mask for when it’s time to go to sleep.

At a minimum, you’ll wake up feeling more refreshed. Best-case scenario: You’ll live longer.

Get plenty of natural light by day: Take a walk outside in the morning. At the office, put your desk near a window.

Invest in a bright light — one that delivers 1,000 lux (a measure of light intensity) or more of blue-hued light at eye level — to put on your desk at work.

Studies show that most office environments are too dim to stimulate the positive, alerting effects of light by day.

One 2014 study by Northwestern University researchers found that people who got most of their bright light exposure before noon were about 1.4 pounds leaner on average than those exposed to most bright light in the evening.

Start powering down at dusk: Use programs f.lux and other apps that automatically shift screens on phones and laptops to more orange-red longer-wavelength lights at night. Several lighting companies, including GE, are also rolling out household bulbs that change wavelengths as the day goes on.

Go camping for the weekend: A recent study by University of Colorado-Boulder researchers found that as little as 48 hours spent in the woods, with no artificial light at night and as much as 13 times more natural light by day, prompted campers to shift into nighttime physiology (signaled by a rise in melatonin) 1.4 hours earlier. They also fell asleep earlier than others who didn’t go camping and were less groggy Monday morning.

Charles Czeisler, PhD, MD, chief, Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Boston.

Randy Nelson, PhD, chairman, department of neuroscience, Ohio State University.

National Toxicology Program workshop: “Shift Work at Night, Artificial Light at Night, and Circadian Disruption.”

NASA website: “Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects).”

American Medical Association. “Report of the Council on Science and Public Health: Human and Environmental Effects of Light Emitting Diode Community Lighting.”

Richard Stevens, PhD, professor, University of Connecticut School of Medicine.

Chang, A.M. PNAS, November 2014.

Figueiro M.G. Lighting Research and Technology, May 5, 2015.

Cheung, I. PLOSOne, May 2016.

Reid, K. PLOS One, April 2014.

Rybnikova, N.A. International Journal of Obesity, January 2016.

Nelson. Molecular Psychiatry. August 2014.

Maltese, F. Intensive Care Medicine, March 2016.

David Blask, MD, associate director, Tulane University Center for Circadian Biology.

Schernhammer, E. American Journal of Preventive Medicine, March 2015.

Mariana Figueiro, PhD, light and health program director, Lighting Research Center, Troy, NY.

Phyllis Zee, MD, PhD, chief of sleep medicine, department of neurology, Northwestern University.

Wright, K. Current Biology, February 2017.

Bureau of Labor Statistics.

Bank of America survey.

National Sleep Foundation.

University of Haifa.

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