Lo-LIGHT Therapy Optimizes Wavelength and Intensity
A Safe, Comfortable, and Effective Light Therapy Technology
Researchers at Sunnex Biotechnologies deduced that the unique physiology of the human eye is the reason that high intensity white light is needed for light therapy. Through an understanding of retinal physiology and the mechanisms by which absorption of visible light can influence living cells, they determined that human sensitivity to light therapy would depend on the wavelength (or color) of light, as well as its intensity. Trials were conducted with a variety of different light wavelengths and the low-intensity Lo-LIGHT lamp was invented.
The wavelengths of light emitted by a Lo-LIGHT lamp are in the shorter region of the green visible spectrum, the most effective wavelengths for light therapy. Lo-LIGHT lamps have the same effect on human physiology as a bright white light therapy lamps that are 20 times as bright, and that provide 20 times as much light intensity to the eye. Patents were obtained in the U.S. and Canada for the use of wavelengths from this portion of the visible spectrum for light therapy.
Intensity, Wavelength (Color) and Light Therapy
Light therapy began in 1982 when it was discovered that extending the length of day with high intensity, "bright" visible white light would relieve major depression in an individual who became depressed every winter. This followed on the discovery 2 years earlier that human physiology, like the physiology of other mammals, is sensitive to the effect that visible white light has on an internal biological clock in the brain, if the intensity of the light is high enough.
It had been known that a light sensitive body clock in the brain of most mammals receives information from the eye to regulate circadian (daily) rhythms of physiological activity, as well causing seasonal changes in the animal's physiology and behavior. However, it was not recognized that light affects humans because the human internal body clock does not respond in a similar manner as it does in other mammals to when they are exposured to lower intensities of white light.
In other mammals, circadian and seasonal physilogy were sensitive to light intensities normally found indoors. For example, one could induce changes in seasonal physiology, or rapidly suppress nocturnal serum melatonin levels, or shift circadian phase of other mammals by simply changing the timing of lighting in an animal rooom. Humans didn't respond this way. Even people working the night shift in well lit facilities do not re-align their circadian rhythms to match their work schedules.
While human physiology does repond to high intensity white light, many people find exposure to the high intensity white light needed for effective light therapy uncomfortable and difficult to tolerate. There was also concern that repeated exposure of the eye to the amount of blue light emitted by these high intensity therapy lamps could lead to blindness.
Independent clinical studies have verified that a Lo-LIGHT lamp needs to provide only 250 to 300 lux of light to be capable of inducing the same physiological response in humans as does a "bright light" therapy lamp providing 10,000 lux of white light. 250 to 300 lux of light is the light level normally found indoors.
Lo-LIGHT lamps are safe as well as effective.
Retinal experts have cautioned that repeated exposure to the higher levels of
blue light wavelengths provided by bright light therapy and blue light therapy lamps
can damage the retina and contribute to an earlier onset of age related blindness.
See the effects of bright and blue light on the eye.
Lo-LIGHT phototherapy lamps emit no blue light wavelengths and provides only those visible light wavelengths which are most effective for light therapy. The elimination of blue light wavelengths together with the lower intensity of light from Lo-LIGHT lamps makes the use of these Lo-LIGHT lamps safer than being exposed to normal indoor lighting. For example, because antidepressant medications and lithium sensitize the retina to damage from blue light, researchers selected Lo-LIGHT lamps for studies on combining light therapy with photosensitizing medications. REF 1, REF 2
Misinformation on the Effectiveness of Blue Light for Light Therapy
There has been widespread misinformation regarding the effectiveness of visible light
wavelengths in blue region of the spectrum, (i.e. wavelengths shorter than 480 nm), for light therapy.
It has been claimed blue light contains the most effective wavelengths for light therapy. This is not true.
There is now abundant evidence in the literature confirming the original findings of our trials of the
wavelength sensitivity of humans which found that blue light is not particularly effective for light therapy.
A major study from Harvard University has confirmed that blue light (460 nm) is not more effective for light therapy than white light. This study was authored by many of the researchers whose earlier work is generally cited to support the use of blue light wavelengths in light therapy. This is discussed in more detail here and here.
Independent studies by the USAF and Canadian Defence Department's R&D Centre comparing low intensity Lo-LIGHT lamps with high intensity, "blue enhanced" light therapy lamps found that Lo-LIGHT lamps had a stronger effect on the biological clock than the high intensity therapy lamps. REF