The Light Spectrum & Light Therapy


Light is measured in nanometers (nm), which represents the wavelength of light, or the band of light energy. There are both visible and invisible light types, depending on the nm. The visible light spectrum is the colours in the world that we see, due to the wavelength of light that is reflected off objects. Sandwiched between the invisible ultraviolet (UV) and near-infrared light (NIR) is visible light, which we see as the rainbow of colours. This visible light spectrum is between 380nm and 780nm.

Lucky for us, the different wavelengths of visible and invisible light have different effects on the physical body. We know that UV light leads to sunburn and Vitamin D synthesis, and perhaps you’ve heard of infrared’s anti-inflammatory properties (like in near-infrared saunas). This means, that we can use different types of light intentionally based on our purpose – this is Light Therapy.

For example, In the 1950’s it was discovered at Rochford General Hospital in Essex that exposure to sunlight was an effective treatment for jaundice in newborn babies.  It was later discovered that it was mainly the blue light spectrum that had the beneficial effect on jaundice so we have been using blue light to treat this condition in most hospitals ever since. It wasn’t until the mid 1960’s that it was discovered that light from the red and near infra-red spectrum had a healing effect on the body by reacting to an enzyme in the cell’s mitochondria. This was discovered in Hungary and was not shared with the Western world until the end of the Cold War. This type of light therapy is most recently termed “Photobiomodulation”.

We, at Luminous Health Solutions, use light in a therapeutic way to support the body’s healing mechanisms. Although we mainly use red, near infrared and green light, this article is going to cover the light spectrum and all it’s different therapeutic properties!

Ultraviolet (UV) Light (100-380nm)

This is probably the most popular light we are familiar with – but this is a type we can’t see!  We’ve all felt the burn that comes after spending time in the sun, and we’ve all benefited from the Vitamin D our body was able to synthesize due to the sunshine. Although sometimes used therapeutically, most often UV light is avoided due to things like the risk for skin cancer.  UV light is divided into three categories based on wavelength: UVA (230-400nm), UVB (280-320nm) and UVC (200-280nm). UVC has a strong germicidal effect and is often used inactivate microorganisms. When ultraviolet light heads into the range of 380-450nm, it becomes the colour violet that we see!

Blue Light (380-495)

Blue light has the shortest wavelength, and the highest energy. This means that in the physical body, the light does not penetrate very deeply into the body. There has been lots of information in the recent years warning us of the risks of blue light being emitted from our screens (like disruption to our circadian rhythms and melatonin production), but there are also benefits to blue light! Sunlight is the most significant source of blue light, but there are many artificial sources like fluorescent lights, LEDs, television screens, computer monitors, smart phones and tablet screens. Also, as mentioned above, light from the blue / green spectrum is used to treat jaundice in newborn babies.

Benefits of blue light therapy include:

  • Affects bilirubin molecules (in jaundiced babies) in order to easily be excreted
  • Boosts wakefulness and alertness
  • Helps memory and cognitive function
  • Elevates mood
  • Affects the uppermost layers of skin
    • Destroys acne and blemish causing bacteria
    • Balances PH
    • Positive effect on eczema, rosacea, and psoriasis
  • Assists with sleep disorders

Green Light (495-570)

Green light is a light that we use in our clinic, in our ARRC Lightbed. This light penetrates a little bit deeper than blue light.

Green light therapy benefits include:

  • Helps with skin discoloration and reduces pigmentation
  • Slows down melanin production
    • Meaning that it targets dark spots on skin like age, liver and sunspots
  • Soothes redness and inflammatory problems
  • Assists with sebum oil production
  • Smooths and brightens the skin
  • Stimulates cellular growth
  • Promotes sleep
  • Engages pain-modulating systems
  • Helps with migraines
  • Calms irritated and over-stimulated skin
  • Targets broken capillaries and dark circles

Yellow Light (570-620nm)

Yellow light reaches deeper into the body than green and blue light, at a depth of 0.5-2mm. It is most often used for skin issues, especially those that have redness.

Yellow light therapy benefits include:

  • Skin cell rejuvenation
  • Soothing anti-inflammatory benefits
  • Protects and hydrates skin
  • Heals skin irritation
  • Reduces rosacea
  • UV damage recovery
  • Boosts lymphatic flow
  • Reduces appearance of tiny blood vessels on the face

Red Light (620-750)

Red light has the widest range of benefits, along with NIR. It reaches deeper than any of the light mentioned thus far. Ultimately, red light and all of its benefits stem from its ability to stimulate the production of ATP and eliminate oxidative stress. This in turn works to reduce inflammation, which reduces pain!

Red light therapy benefits include:

  • Stimulates collagen production
  • Decreases pain
  • Speeds wound healing, which is helpful with things like diabetic foot ulcers
  • Reduces scars, wrinkles, and fine lines
  • increases muscle recovery
  • enhances blood circulation
  • anti-inflammatory
  • helps with side effects of chemotherapy
  • helps with joint conditions like rheumatoid arthritis, carpal tunnel and osteoarthritis
  • oral conditions like oral mucositis
  • mends sun damage
  • prevents recurring cold sores
  • tissue repair
  • promotes hair growth in people with alopecia
  • and SO much more

Near Infrared Light (750-1200nm)

NIR penetrates the deepest of all the light waves mentioned here, and it has the ability to penetrate more dense tissue in the body like bone and cartilage. Like UV light, NIR is outside the range of visible light – this means we can’t see it, but it doesn’t mean it’s not there. Like red light, NIR works to reduce inflammation, stimulate the production of ATP, and promote healing.

 Near Infrared light therapy benefits include:

  • promotes tissue and deep wound healing
  • boosts metabolism
  • recharges mitochondria
  • stimulates white blood cell production
  • promotes cell regeneration
  • increases energy and circulation
  • reduces inflammation
  • supports faster recovery after working out
  • provides pain relief
  • promotes anti-aging
  • improves thyroid, hormone, and immune function
  • supports brain and cognitive health


Even though the healing effects of light are not new, what is new is the discovery of the unique healing effects that the various wavelengths of light have on our cells when emitted at specific frequencies and time intervals.

Now that we know that cells in our bodies are filled with light sensitive switches and amplifiers and how wavelengths of light can affect these, we have the ability to use exactly the type we need, to achieve the health goals we have!

Sources: do we “see” using the color of light reflected. light covers a wavelength, mercury lamps to inactivate microorganisms.