Blue Light: Why it is Both Necessary and Harmful

Everything You Need to Know About Blue Light

The topic of blue light has become increasingly prevalent. Unfortunately, the information provided through mainstream media is both misleading and lacking a comprehensive look at the data. Blue light has both positive and negative benefits and is actually a critical component for optimal health. When utilized correctly, it can lead to improved alertness, energy, cognition, and mood. Overexposure, however, can lead to eye damage, skin damage, poor sleep, and a disruption of the circadian rhythm.

What is Blue Light?

Blue light falls between the wavelengths of 380-500nm, has one of the shortest wavelengths of light and the most energy. Before artificial lighting was invented, the only source was from the sun during the early morning hours to early afternoon. Now, however, blue light is delivered to us both naturally from the sun and artificially from indoor lighting and electronics. So what makes artificial light different from natural?

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Naturally Occurring Blue Light

Again, before artificial lighting, we were only exposed to blue light from the sun. The sun’s natural light, however, is made up of the full spectrum of color. We never received just one singular color. The other colors present in the sun’s light help balance out the effects of all the colors. Blue light specifically, increases energy, boosts attention, and improves mood. Too much, however, without other lights to balance it out or after the sun has set can lead to adverse effects like poor sleep quality, eye damage, increased fine lines, and wrinkles, to name a few.

Where Science Muddles the truth

I’ve heard scientists and eye doctors claim that blue light is not at all harmful because the light emitted from our artificial lighting and electronics are nowhere near as bright as the light coming naturally from the sun. This, however, is not the only factor that must be considered when looking at the impact of blue light.

First, as mentioned above, blue light is a very high energy light that can be extremely stimulating. In natural daylight, we are receiving the full spectrum of both visible and invisible colors which all help balance each other out. When we are staring at a computer screen that is only emitting blue light without any other colors, this high energy wavelength becomes damaging.

Second, these eye doctors and scientists are not taking into account how blue light affects our entire system, not just the eyes. From an evolutionary standpoint, we only received blue light during the morning to early afternoon hours when the sun is at its brightest. This day time exposure signals the production of hormones like serotonin, cortisol (in healthy amounts), and other energy-boosting, mood-enhancing, and cognitive-enhancing hormones. As the sun begins to sink it emits yellows, oranges, and reds which signal our body to produce melatonin and prepare for sleep.

How We Absorb Blue Light

By now, it is common knowledge that our eyes are able to see and absorb light. But did you know that your skin can absorb light as well? Light is, after all, just energy and our skin is the largest most absorbent organ of our bodies! What does this mean? While reliable blue light blocking glasses can go a long way to help reduce eye strain, headaches, and other vision-related problems, they are not enough to reduce the full-body effects. I will get into specific ways to protect yourself from too much blue light exposure below. For more information on light and energy read my article on Chromotherapy.

Benefits of Blue Light (In the Right Context)

With all the negative press blue light has received over the last few years, many assume it is altogether harmful and should be avoided completely. Unfortunately, like most health topics, this is not a black and white matter. Blue light exposure during day time hours can be extremely beneficial and even necessary to optimal health.

Increased Energy, Alertness and Mood

As previously mentioned, exposure to blue light during the day time stimulates the production of hormones that help wake the mind and body. Some of the hormone production triggered by blue light exposure include:

Cortisol: Although cortisol gets a bad wrap as the “stress” hormone, we need it in appropriate doses to be optimally alert and awake. Sunlight exposure first thing in the morning stimulates the production of cortisol which signals our body to wake up.

Serotonin: a major hormone that affects mood, appetite, and sleep. Serotonin is also critical in the mornings because it will later lead to the production of melatonin. Without this day time production of serotonin, our bodies will not be able to produce as much melatonin to allow for optimal sleep.

Gaba & Dopamine: Gaba is a hormone responsible for producing feelings of calmness and dopamine helps stimulate alertness and a sense of well being.

Neuropeptide Y and Gastrin Releasing Peptide: two major hormones that make us feel hungry. This is important during the day to ensure we are consuming nutrients to fuel us, but blue light exposure after dark may be one reason why you can’t stop eating at night. (Source)

Seasonal Affective Disorder

For those living in areas like Alaska where sunlight is not available for normal periods of time, a high lux blue light can be extremely helpful during day time hours and especially immediately upon waking to trigger the production of these hormones. This helps prevent or lessen Seasonal Affective Disorder (S.A.D.).


Blue light is highly anti-bacterial which can be useful in a variety of situations including decontamination of hospital rooms and the treatment of acne. It can kill bacteria that cause hospital-acquired infections (S. epidermidis, S. aureus, S. pyogenes, C. perfringens, E. coli, P. aeruginosa, and K. pneumoniae) (source, source).

It can also kill acne-causing bacteria on the skin (Propionibacterium acnes) (source, source)

Negative Effects of Artificial Blue Light

Disrupts Circadian Rythm & Sleep Quality

All the reasons blue light is amazing during the day are also all the reasons it can be extremely disruptive at night. Exposure in the evenings during and after sunset disrupts your natural circadian rhythm which affects an array of functions.

As previously stated, blue light stimulates hunger and therefore exposure at night can trigger our bodies to continue eating even when more nutrients or calories are not needed. Along with this, it triggers cortisol production for energy and suppresses the production of melatonin. These two functions combined lead to incredibly poor sleep quality.

“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.

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).” (source).

Irritation & Eye Damage

Extensive exposure to blue light, particularly from artificial sources can lead to eye strain, blurred vision, dry eye, headaches, and fine lines or wrinkles around the eye area from minor squinting. More severe eye damage is also possible including permanent damage to the retina which can lead to macular degeneration and even blindness (source).

Damages Skin

In the skin, overexposure to blue light can lead to increased oxidative stress. We know from countless studies that oxidative stress on the skin without enough antioxidants leads to the aging of the skin (increased fine lines and wrinkles, redness, hyperpigmentation) (source, source).

How to Protect Yourself

Morning Sun Exposure

Go outside as soon as you can in the morning once the sun has risen. If you are awake before the sun, as soon as it rises take even just 5 minutes to step outside and expose yourself to the natural spectrum of sunlight. This sets off a cascade of hormone production that will lead to better energy, focus, and mood during the day and better sleep at night.

Sun Exposure Throughout the Day

Get outside regularly throughout the day to expose yourself to natural blue light mixed with the other colors of the visible spectrum. I try to go outside for at least 5 minutes every hour to keep my circadian rhythm on track. While this may not be realistic for everyone, most bosses will not complain about a 5-minute outdoor break. If you can’t manage to fit this in, try eating your lunch outside.

During raining weather consider bringing a red light therapy device to work to sit under while eating lunch or even while working.

Blocking Glasses

Wear blue light blocking glasses indoors even if you are not working on a computer or using other electronics. This will help protect from overstimulation resulting from LED lighting and electronics. Bon Charge (Formerly Blublox) is a fantastic brand that blocks 100% of blue light. P.S.  Use discount code: LAL

Color Mode of Electronics

Change the color mode of your electronic devices in the settings or by using apps like Iris Tech to make the appearance redder. This may be strange to the eyes at first, but I promise you will adjust and it will be worth it.

Cease Exposure During and After Sunset

This is critical. While all light exposure after sunset has been found to disrupt melatonin production, blue light has been found to suppress melatonin production two times as much as other wavelengths of visible light.

This means not using electronic devices and artificial lighting. Listen, I get it…a tv show at the end of a long day can be relaxing or even reading a book in bed lit by a lamp. If you absolutely cannot cease all exposure at night it is critical that you are using red/amber tinted 100% blue light blocking glasses.

Consider changing the light bulbs in your appliances or simply purchasing red night lights you can plug-in throughout the house. I like these because they turn on automatically when it gets dark and they turn off automatically when it senses light. Bon Charge now also has an amazing line of bluelight-free light bulbs and lighting options.

Red light does not suppress melatonin production so it is safe to use at night. There is definitely an adjustment period when you decide to stop using bright lights after sunset, but it is not as long as you might think. I found that just 3-4 days after switching to only red light after dark I was used to the dimmer lighting.

Red Light Therapy

There is extensive research behind the benefits ofred light therapy(full science-based article coming soon on this). Ever notice the soothing effects of a campfire, candle or red light? Benefits include increased collagen production, reduced inflammation and pain, reduced fine lines and wrinkles, quicker wound healing (including muscular injuries and scarring), improved skin tone, reduced hyperpigmentation, increased ATP production in the cells and improved sleep.

I use a red light therapy device daily for healthy, younger skin and to improve my cellular function through the increased ATP production (this is the energy of the cell). Red light therapy can help balance and even heal the damage caused by excessive blue light exposure. In the evenings, red light is the best choice for indoor lighting because it DOES NOT suppress melatonin production.

Often, the media gives us a very black and white view of any given health topic. Unfortunately, life is very rarely that simple and this holds true for the topic of blue light. It is not simply something we can write off and wholly “bad”, nor is it always good.

However, understanding the purpose blue light plays in our everyday lives and physiology can help us begin to optimize our exposure in healthier ways.

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