You know that feeling you get when you first wake up, draw back the curtains, and are greeted by the bright, shining sun? You feel the warmth on your skin, and feel energized, happy, and excited for the day ahead? It’s not all in your head! The electromagnetic spectrum of light does indeed play a huge role in our bodies physiology, not only with the visible light spectrum but from infrared wavelengths as well.

 The Light Around Us

The health benefits of light aren’t often discussed, but light is crucial to our overall well-being. Like water, sleep, and food, light is essential for our cellular function and energy production. Historically, we used to be exposed to much more natural light. Our ancestors would rise with the sun, work outside during the day, and spend the evening hours by fire or candlelight, both of which emit red and infrared light. This rhythmic living with the rising and setting sun naturally tuned their circadian cycle.

In today’s modern world, we are generally exposed to more artificial light than natural and are constantly bombarded by the blue light on our cellphones, computer screens, televisions, and artificial lighting in our homes, schools, and workplaces. Studies are showing the negative effects on our health as a result. (1)  Just as we can suffer from malnutrition due to a diet lacking in all the essential nutrients and amino acids the body needs, we too can suffer from poor exposure to light, known as mal-illumination. You likely have heard of Seasonal Affective Disorder (SAD), this is but one example of how lack of exposure to light manifests in the body. Poor light exposure wreaks havoc on our circadian rhythm, mood, and energy levels.

Let’s take a deeper look at the types of light and how the body utilizes specific wavelengths to set circadian rhythm, synthesize hormones, and create energy on a cellular level- all of which synergistically impact your overall health.

How Light Affects Us—Three Pathways

Wavelengths of light affect the body in 3 ways. First is through our vision. When light enters the eye, it hits the retina, and cells called photoreceptors turn this light into electrical signals. These signals travel to the brain via the optic nerve, where the brain then turns these signals into the images we see. The human eye can only detect visible light on the electromagnetic spectrum, which is seen as the colours of the rainbow. 

The second way light affects the body is through a non-visual pathway. This is the visible light we can see, but it acts on the body’s physiology by triggering hormone secretion, namely serotonin and melatonin, which are crucial for regulating our circadian rhythm. Exposure to light, specifically blue light, interacts with melanopsin receptors in the retina, signalling the production of melatonin. These receptors are extremely sensitive to blue light. We need blue light to regulate circadian rhythm, with the ideal time for exposure early in the day.

Finally, light affects us through a process called biophotomodulation. Biophotomodulation (or photobiomodulation) can be likened to the process of photosynthesis. Just as plants need the sun to thrive, humans require direct sunlight exposure on the skin to synthesize Vitamin D, and to stimulate energy production in our cells. The effects of sun exposure on the skin result from the interaction of photons from the sun with photosensitive molecules in the skin called opsins. Many of the cellular responses in the skin are modulated by these opsins, also referred to as the “eyes of the skin”.

The Electromagnetic Spectrum And 5 Types Of Bioactive Light

The electromagnetic spectrum spans from radio waves to gamma rays and is measured in nanometers. The longer the wavelength, the lower the frequency. The shorter the wavelength, the higher the frequency. The visible light spectrum spans from 440-780 nanometers, only making up around 1% of the electromagnetic spectrum. We view visible light as the colours of the rainbow. Sunlight is composed of 3-5% UV light, 42-43% visible light, and 52-55% infrared light (which we perceive as heat). (2)  We are focusing on the visible, infrared, and ultraviolet waves and how these types of light affect the body. 

Visible Light Spectrum

There are 5 types of bioactive light. Bioactive means these wavelengths of light affect the function of our cells.

1) Blue Light

You are likely familiar with blue light, as we tend to hear a lot of buzz around reducing our exposure to this type of light, but did you know blue light is critical to our health and well-being? It has the shortest wavelength, between about 440 and 495 nm. The best source of blue light comes straight from the sun. Blue light is an energizing, high-frequency wavelength that plays a crucial role in regulating our daily circadian rhythm. 

Morning light signals your hypothalamus and all corresponding organs and glands to wake up and be alert. The low solar angle of the morning sun helps stimulate the retinal ganglion cells in our eyes called melanopsin, which triggers the production of melatonin, which we need to fall and stay asleep at the end of our day. As a blue light-sensing protein, melanopsin is present in 5000 neurons in the eye, which literally hardwires the circadian clock in the brain. (3)  Aim to start your day by getting outside as close to sunrise as possible to get exposure to this beautiful, energizing blue light. Spending a few minutes outside, or better yet, heading out for a brisk walk will get that blood flowing, clear your mind, and stoke your digestive fire for the day ahead. Leave the sunglasses at home to allow your retinas to absorb this wavelength of light. DO NOT LOOK DIRECTLY AT THE SUN. While natural blue light from the sun is beneficial to health and well-being, we need to be mindful of our exposure to artificial sources. Keep reading to learn more about the dangers of this ‘dirty’ type of light.

2) Ultraviolet Light 

UV light is categorized into 3 main types—UVA, UVB, and UVC based on their wavelengths. This light is not part of the visible spectrum. Almost all of the ultraviolet radiation that reaches the earth is from UVA and UVB. Both types can affect health, but UVA penetrates deeper and is more constant throughout the year. UVA has a longer wavelength and is most commonly associated with premature aging. UVB has a shorter wavelength, stimulates the production of Vitamin D in the skin, and is associated with sunburn and an increase in cellular damage.

Safe exposure to ultraviolet rays is needed to synthesize Vitamin D.  The right time of day is critical—between the hours of 10 am and 3 pm is ideal.  Aim to expose large areas of the body—legs, arms, and abdomen for a short period of time. 10-30mins a day is a great place to start, but it does need to be without sunscreen, which blocks that UVA/UVB light. Start on the lower end for exposure, and gradually increase. You don’t want to be burning the skin at all. It is recommended to get your Vitamin D levels tested at the end of summer when your Vitamin D level should be at its highest. This is important to know if supplementation (and how much) is needed throughout the winter months ahead when our sunlight exposure often drops dramatically.

3) Red Light

Red light is the longest wavelength in the visible light spectrum (620-750nm), given off by the sun, firelight, and candlelight. This wavelength is more prevalent in the evenings, as the Earth’s atmosphere filters much of the intense, blue light of daytime. Our bodies are programmed to respond to these daily changes in intensity and colour. This warmer, longer wavelength of light triggers the release of melatonin and signals our bodies to prepare for rest. Red light acts on the mitochondria of our cells by increasing cellular energy through the production of adenosine triphosphate (ATP). 

4) Near Infrared

Near-infrared(NIR) light is the closest in wavelength to the visible light spectrum at 750-1200nm, though we cannot see this light. Both red and near-infrared light increases mitochondrial function by boosting energy production at a cellular level. The mitochondria are the powerhouses of our cells! These wavelengths aid in stimulating the production of adenosine triphosphate (ATP) by interacting with the enzyme cytochrome c-oxidase. Our cells are constantly making and using ATP. The more ATP our cells can produce, the more energy we will have to go about our daily lives. ATP is the primary energy source for many biological and physiological processes in the body (growth, movement, sleep, heartbeat, homeostasis).

mitochondrial health

Adequate energy production is the hallmark of a healthy cell. We need to keep our mitochondria fueled and performing optimally for us to be in good health. Failure to produce ample energy can lead to improper organ and cellular function, resulting in chronic disease. Experts in the field of mitochondrial health have found that poor functioning of the mitochondria is the root of all diseases in the body.  Red and near-infrared light therapy has been shown to increase cell proliferation and migration, and assists in modulating levels of cytokines (proteins made by certain immune cells), promoting increased immunity and many metabolic processes within the body.

5) Far Infrared

Far infrared light produces no visible light, rather we feel it as the warmth from the sun, fire, or infrared sauna. Far infrared (FIR) is closest in wavelength to microwaves on the electromagnetic spectrum (1500-10,000nm). Unlike red and NIR which are absorbed by cytochrome enzymes, FIR light improves the body’s metabolic response by temporarily increasing overall temperature. When far infrared waves come in contact with the bodily tissues, it causes the molecules to vibrate, which produces heat and causes a rise in body temperature. A great example of this is an infrared sauna. Instead of a traditional sauna which uses high temperatures to produce sweat, infrared saunas use far infrared wavelengths to heat the body as opposed to the ambient temperature. An infrared sauna provides the same benefits as a traditional wet/dry sauna with sweat production, detoxification through the skin, and increased heart rate and circulation, however, some people find an infrared sauna to be more comfortable to use.

‘Dirty’ Light and Effects on the Body

As mentioned previously, our increased exposure to artificial lighting is wreaking havoc on our health. Complaints of disrupted sleep cycles, eye strain, headaches, and lethargy are widespread and common issues. The advent of the technological age has brought forth many advancements in how we live our lives, and connect with each other, and the world at large, but at what cost?

relationship with light

LED, fluorescent, and compact fluorescent lights have replaced natural lighting from fire and candles our ancestors knew so well. These types of lightbulbs all produce flicker, also known as the stroboscopic effect, or Critical Flicker Frequency (CFF). While imperceptible to the naked eye, CFF is the frequency of flickering that is perceived as continuous, unlike lights flickering in a thunderstorm, for example. This flicker is known to cause headaches, eye strain, increased heart rate, dizziness, nausea, and even trigger seizures. (5)  You may have experienced one or more symptoms in your own daily life, especially if working in an office setting—in front of a computer screen and under fluorescent lighting all day. Our children too are exposed to a barrage of ‘dirty’ lighting. Fluorescent lighting at school, straight home to complete homework on computers, screen time on tablets, cellphones, video game consoles, and LED lights in bedrooms- all this artificial light exposure adds up quickly. Not only does this type of artificial light emit flicker, but also exposes us to an unnatural amount of blue light.

We know that blue light is stimulating, energizing, and vital to our health, however, we need to be mindful of our exposure in the latter part of the day, especially the hours leading up to sleep. While blue light has clear benefits, it can also have adverse effects on health. We are constantly bombarded by blue light from our cell phones, computers, various screens, and artificial lighting. Exposure to blue light later in the day actually suppresses melatonin secretion—the hormone produced by the pineal gland that plays such a huge role in circadian regulation. The evening hours are the time to use blue-blocking glasses and minimize screen time and artificial lighting.

Red Light Therapy and Benefits of Use

The use of light therapy dates back to 1893 when Nobel Laureate and Danish physician Dr. Niels Ryberg Finsen discovered the use of light radiation to treat smallpox and later, lupus. More recently, in 1993, NASA researchers conducted an experiment that used red wavelengths of light to stimulate the growth of plants. (6) While that experiment was indeed a success, an interesting byproduct was that researchers who were exposed to this red light noticed rapid and unexpected healing of their own skin afflictions.


Red light therapy, also called low-level laser therapy (LLLT), uses light from the red and infrared wavelengths of the electromagnetic spectrum, through direct exposure to the skin with the use of a lamp, device, or laser. Most other wavelengths of light are unable to penetrate the layers of the body, whereas red and infrared light reaches deep into the body’s tissues, to reach our blood, bones, nerves, and organs to promote healing. It produces no heat and cannot be felt. Red light specifically is absorbed by the skin and is able to penetrate the subcutaneous layer, while near-infrared reaches much deeper into muscle, bone, and interior tissues. It increases mitochondrial function by boosting energy production at the cellular level (ATP production) and helps the body make and use ATP more effectively. Red light therapy activates the sympathetic nervous system and controls inflammatory response.

In my clinic, I utilize a Bioflex laser to help patients find relief from a wide variety of aches and pains. Bioflex is a powerful, class 3B laser that uses superluminescent diodes (SLDs) to penetrate and target specific tissues in the body. These light diodes are collimated, with very little diffusal of light (hence laser). This allows a reduction in the number of placements of the laser during treatment. With the Bioflex I am able to alternate between specific red and near-infrared wavelengths depending on the patient and protocol. If you are local to the Ottawa area and are interested in learning more about this treatment option at my clinic you can find out more information HERE.

A great option for home use is a red light panel. With several sizes and price points, these devices are an easy and affordable place to start incorporating red light therapy into your routine.

Red Light Therapy

Light panels use ‘warm’ LED (light emitting diode) lights to deliver red and near-infrared waves to the body in a wide-angle continuous light.

Studies have shown red light therapy to have a multitude of health benefits:(7) 

  • Stimulates healing for a wide variety of skin conditions-psoriasis, eczema, rosacea
  • Activates the lymphatic system-a key part of immunity
  • Lowers the effects of oxidative stress associated with aging, while enhancing collagen production
  • Pain reduction -joints, arthritis, speeds muscle recovery
  • Improves mood and cognitive function
  • Increases blood flow/circulation, helping to oxygenate cells and tissues
  • Reduces inflammation
  • Enhances fertility
  • Speeds wound healing
  • Improves metabolism

Essentially everyone can benefit from adding red light therapy to their wellness lifestyle.

7 Easy Hacks To Improve Your Relationship With Light 

Now that you understand the crucial role light plays in the body and its effects on physiology, here are simple steps you can take to reap maximum benefits in your daily life.

Greet The Sun—Head outside as close to sunrise as possible, for exposure to that stimulating and energizing natural blue light. This alerts your body to start the production of melatonin needed to fall and stay asleep later in the evening. Set yourself up for a good night’s sleep! This is also the time of day to utilize a SAD lamp/lightbox which mimics the broad spectrum of the sun while filtering out UV radiation. 

Soak Up Some Rays—Short, safe exposure to UVB rays on your skin between the hours of 10 am and 3 pm to synthesize Vitamin D. Aim for 10-20 minutes of sunscreen-free time to begin with. Start small and gradually increase time in direct sun. Be cautious to avoid skin burning and overexposure.

Ban The Bulbs—Wherever possible, swap out fluorescent and compact fluorescent lightbulbs in favour of incandescent or halogen bulbs. Halogen and incandescents are preferred as they emit more infrared light, and are closest to the sun’s broad spectrum of light. CFLs and fluorescents are to be avoided as both have a toxicity factor with the presence of mercury, as well as excessive flicker which creates unnecessary environmental stress on the body. If using LED lighting, always choose the ‘warm white’ (2000-3000k) to minimize the effect of blue light. Never use the dimmer function on LEDs as this increases flicker and contribute to ‘noisy’ light exposure.

Ease Your Eyes—There are several apps and software available on the market that are easily installed on devices and PCs to reduce exposure to blue light. Iris software and f.lux are just a couple of examples which gradually regulate the amount of blue light emitted by devices depending on the time of day or night. They match screen brightness to the light around you, optimize screen pulsations, and reduce flicker. These tools can help reduce stress on your sensory system, eye strain, headaches, and macular degeneration associated with device use.

Block The Late Day Blues—The late afternoon and early evening hours are crucial for reducing exposure to artificial blue light in your environment. This is the time of day to put on blue light-blocking glasses when using screens and devices. Ideally no exposure to blue light in the 2 hours leading up to bed. Use orange-coloured lenses in the late afternoon and early evening, and red-tinted glasses at sundown. The red-hued lenses mimic the red light from sunset and firelight, which triggers the release of melatonin from the pineal gland produced earlier in the day, and signals the body to prepare for rest. Special consideration for those who may work evening and overnight shifts—having a pair of yellow or orange glasses on hand may help the fatigue brought on by nighttime exposure to artificial and fluorescent lighting. Also, getting outside for a postprandial walk after dinner not only exposes you to the red light of natural sunset but will also aid digestion and help regulate blood glucose levels. Stack those health benefits! I recently came across an amazing 3-in-1 pair of glasses that actually do all three! You can find more information about them HERE.

Lights Out—We want to minimize all exposure to light throughout the night, especially bright white and blue light. Consider using a red incandescent lightbulb in the bedroom or red night light in a child’s bedroom or nursery if absolutely needed. This warmer light is less assaulting on the senses when you must get up. You know the feeling when you get up to use the restroom in the middle of the night and want to ‘stay sleepy’ to be able to fall back asleep with ease? Ideally, your sleeping area should be pitch dark to allow your body to rest and regenerate. If you hold up your hand and can see it in front of you, your room is not dark enough!  Absolutely avoid the temptation to pick up your phone in the middle of the night—it shouldn’t even be in your bedroom. Even brief exposure in the middle of the night disrupts your circadian rhythm and makes it far harder for your brain to fully shut down, keeping you in lighter stages of sleep for the remainder of the night. If you are a night owl, try to gradually start shifting your bedtime earlier as melatonin is at its peak at midnight. For a deeper dive into sleep and the circadian cycle, check out my previous blog post on sleep.

Red Light Therapy—Using a red light panel, targeted laser, or infrared sauna on a regular basis has innumerable benefits to the body. The best time of day to utilize this therapy is as close to sunrise and sunset as possible, as red and near-infrared rays are found in the rising and setting sun. Like any exposure to evening light, red light therapy should be done at least an hour or two before bed, to give the body ample time to prepare for rest and regeneration. While red light therapy promotes deeper and better quality sleep, some individuals may find the light exposure in the evenings to be stimulating, while others may find it relaxing. Experiment for yourself to see which time of day best suits your body and schedule. 

With so many red light therapy products on the market, it can be dizzying to determine which product may be right for you. One of my favourite tools for at-home use is the Joovv red light panel. It comes in a variety of different sizes and price points, making it a great choice to start reaping the benefits of red light therapy in the comfort of your home. Red light therapy boasts a long list of benefits from pain reduction, increased collagen production, and improvement in mood and cognition, to relief from eczema, psoriasis, acne, and much, much more! With consistent, regular use, you too can experience increased energy, better quality sleep, and overall better health.

There you have it! Hopefully, I’ve ‘shed some light’ on how powerful the light in our environment really is and inspired you to take a deeper look at your own relationship with light. 


(1) Health effects of artificial light. Health Effects of Artificial Light – European Commission. (n.d.). Retrieved October 7, 2022, from
(2) Rose AlMayaleh. Light: The Key to Master your Sleep and Energy. VivaRays. (n.d.). Retrieved October 17, 2022, from
(3) YouTube. (2022, April 18). Using light (sunlight, Blue Light & Red Light) to Optimize Health | Huberman Lab Podcast #68. YouTube. Retrieved October 8, 2022, from
(4) Levy, J. (2022, March 15). Have you tried red light therapy? Dr. Axe. Retrieved October 8, 2022, from 
(5) Inger, R., Bennie, J., Davies, T. W., & Gaston, K. J. (2014, May 29). Potential biological and ecological effects of flickering artificial light. PloS one. Retrieved October 13, 2022, from 
(6) NASA. (n.d.). Lighting the way for quicker, Safer Healing. NASA. Retrieved October 13, 2022, from
(7) Chung, H., Dai, T., Sharma, S. K., Huang, Y.-Y., Carroll, J. D., & Hamblin, M. R. (2012, February). The nuts and bolts of low-level laser (light) therapy. Annals of biomedical engineering. Retrieved October 16, 2022, from 

General References: 

Martel, Anadi. Light Therapies: A Complete Guide to the Healing Power of Light. United States: Inner Traditions/Bear, 2018.Whitten, A. (2018). The Ultimate Guide to Red Light Therapy: How to use red and near-infrared light therapy for anti-aging, Fat Loss, Muscle Gain, and performance enhancement. Createspace Independent Publishing Platform.
General HealthHow Light Affects Us and The Benefits of Red Light Therapy