How 300-400 Lux of Lo-LIGHT has the same effect as 10,000 lux of white light

Light Therapy that Optimizes Wavelength as well as Intensity

Q. Why do people commonly refer to light therapy as "Bright Light Therapy"?

A. Light therapy began when it was discovered that people are sensitive to seasonal changes, and that it is the effect that light has on the internal biological clock in the brain that is responsible for this. In mammals a light sensitive body clock in the brain receives information from the eye that helps regulate circadian (daily) physiological rhythms, as well as seasonal changes.

While other mammals respond to low levels of light intensity, usually much lower than those normally found indoors (i.e. much lower than 400 lux), humans uniquely need exposure to high intensities of white light to influence this light sensitive region of brain that is involved in regulating their internal body clock. This light sensitive region of the brain is not involved in vision, but does regulate the body clock. Because early studies indicated humans needed ocular exposure to high intensities of light to stimulate this region of the brain, light therapy originated with "bright" light, usually 5,000-10,000 lux light boxes. (more background on our "History of Light Therapy" page)

Q. What is Low-Intensity Light Therapy and Why is it Safe?

In the early 1990's, researchers at Sunnex Biotechnologies theorized that the reason humans needed to be exposed to high intensities of light to influence this light sensitive region of the brain was due to the unique physiology of the human eye. They determined that light therapy would therefore be sensitive to wavelength as well as intensity. Subsequent studies determined that low intensities of light with wavelengths from the shorter region of the green visible spectrum were capable of inducing an equivalent physiological response, as measured by nocturnal melatonin suppression, as does white light that is about 20 times as bright - hence our patented low-intensity light therapy technology.

Some of the visible blue wavelengths that were thought to be capable of stimulating the light-sensitive region of the brain not involved in vision are in the range of the light spectrum that causes excessive stress to the eye. These are wavelengths shorter than 480 nm, which the eye sees as the colour blue - hence the term "blue light hazard". There is considerable evidence that the stress caused to retinal tissues when blue wavelengths of light are absorbed in the eye contributes to the aging of the eye, which leads to age-related blindness. (See our pages on the effects of bright and blue light on the eye.) Recent studies now indicate that monochromatic blue (479 nm) wavelengths of light are in fact not much more effective than polychromatic white light.(Revell and Skene. Chronobiology International; Nov 2007- Ref)

Sunnex Biotechnologies'' Lo-LIGHT phototherapy lamps screen out these harmful wavelengths of (blue) light and provides only those wavelengths which are most effective, but do not increase normal levels of retinal stress. Thus a Sunnex Biotechnologies Lo-LIGHT using GreenLIGHT technology is not only more comfortable, but is also safe.

Q. Is a Sunnex Biotechnologies' Lo-LIGHT as effective as bright light therapy boxes?

Studies with Lo-LIGHT lamps have shown that low intensity (about 300 - 400 lux) Sunnex Biotechnologies GreenLIGHT has the equivalent physiological effect as does bright light (6,000 - 10,000 lux). In addition to clinical trials with Lo-LIGHT lamps for winter depressives, controlled studies by Benedetti et al with Sunnex Biotechnologies' GreenLIGHT technology demonstrated dramatically improved responses from people with non-seasonal major depression, (both unipolar and bipolar) who are starting on an antidepressant medication. These studies used low intensity light therapy because most anti-depressant medications increase the risk of retinal damage from bright/blue light, while the Lo-LIGHT is not harmful to the eye. Reference 1 Reference 2

More recently, Benedetti et al ( J Clin Psychiatry, Dec 2005 and Archives of Gen Psychiatry, Feb 2007) found that low intensity (400 lux) of green light in conjunction with sleep deprivation induced rapid and sustained amelioration of depression in patients with bipolar disorder.

Additional evidence of the Effectiveness of Sunnex Biotechnologies GreenLIGHT technology.

In addition to studies on depression, independent studies with the Lo-LIGHT tower by the Canadian Defense Department's R&D Centre and the USAF have found that Sunnex Biotechnologies' Lo LIGHT is twice as effective as blue light emitting light therapy devices like the Litebook®, even though it provides only 1/20th of the light intensity (energy). Ref These results are consistent with those found by the U.S. Coast Guard's R&D Center. After years of trials measuring the physiological response to exposure of Sunnex Biotechnologies GreenLIGHT technology in laboratories and on operational military and commercial vessels, the U.S. Coast Guard used GreenLIGHT lamps to develop light management protocols to regulate circadian phase in their Crew Endurance Management System (CEMS) for commercial vessels operating on inland or coastal waterways.

Q. Does research on "bright light" therapy apply to the low-intensity Lo-LIGHT Lamp?

A. The authoritative Cochrane Reviews on the use of light therapy for non-seasonal depression extended the definition of "bright light therapy" to the range of 400-10,000 lux in order to include Sunnex Biotechnologies' Lo-LIGHT in their assessment of active bright light therapies. This Cochrane Review also rated the study using the Sunnex Biotechnologies Lo-LIGHT as one of only two studies out of the 20 that were able to satisfy the inclusion criteria for this review that achieved a quality standard of "A", as compared to the quality standard rating of "B" that the other studies included in the review achieved. Click for more information on The Cochrane Review on Light Therapy for Non-Seasonal Depression.

Green Light vs Blue Light: Efficacy and Hazard to Vision

As the awareness that the effectiveness of light therapy is dependent on wavelength as well as intensity has grown, there has been an attempt to promote light therapy made up of, or supplemented with increased levels of blue light. Because of the substantial risk to vision that these products pose to the user, we have prepared a technical discussion comparing the scientific basis of Sunnex Biotechnologies patented low intensity green light therapy with that of blue light therapy. For an analysis of GreenLIGHT therpy vs blue light therapy Click Here.

The compelling evidence that has accumulated from numerous studies over the past few years regarding the role that exposure to blue visible light plays in the development of AMD (Age-related Macular Degeneration) has led leading experts to caution the public that the detrimental effects of oxidative stress in the retina caused by blue light exposure accumulates over a lifetime and contributes to the development of AMD and that people should therefore restrict exposure to blue light wavelengths as much as possible. For more information on this subject can be found at the risk to vision from Bright and Blue Light Therapy- Click Here

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