Blue-light Hazard



There has been a recent appearance on the market of a number of small and sometimes hand-held light therapy devices incorporating either blue or white LEDs. These products are being advertised as effective treatments of Seasonal Affective Disorder SAD. Britebox light therapy has reviewed the data on these products and has concluded that they are not adequately researched and may indeed cause an early onset of Age Related Macular Degeneration.



We will, however, draw on the conclusions of the Seasonal Affective Disorder Association (SADA) to highlight our position on Blue and White LED’s:



An article by Amanda Cross SADA Science and Technical Officer (October 2007)



It is indeed true that there have been studies which have indicated that melatonin suppression is under the control of specific wavelengths of light, and that blue or white LEDs may be effective in the treatment of SAD. However, (and this is a big “but”) there does not yet appear to be enough scientific evidence to be sure of the effectiveness and/or any long-term side effects of such blue or white LED devices in the treatment of SAD.



The first disadvantage of the clinical trials which have been carried out to date, is that most of them have been too small to give conclusive results, with often less than 30 subjects participating. The results of such trials must be interpreted with caution and the results of the trials indicate that larger trials are now required in order to provide more definitive information about the efficacy and safety of LED devices.



The second problem is with regard to the safety of such devices and the potential long term effects of using LED products. It is now widely accepted that traditional 10,000 Lux bright white light is safe. However questions have been raised about blue light safety and the use of white and blue LEDs, both of which emit light with peaks in the blue end of spectrum.



Light-induced photochemical damage to the eyes is particularly related to light at the blue wavelength. This type of damage to the retina is known as “blue-light hazard”. Older people are particularly susceptible to such light induced retinal damage.



It should also be remembered that recent studies most certainly do not establish blue light or LED products as uniquely effective for SAD. Even the manufacturers of such alternative devices would have difficulty in discounting all of the valuable and universally accepted research regarding the use of bright white light. The consensus, at least amongst the scientific community, seems to be that before such a bold assertion regarding a higher efficacy of LED products can even be hinted at, then many further and larger studies with different comparison conditions must be carried out.



Due to the uncertainty surrounding the effectiveness and safety of blue light and LED products. SADA does not currently therefore recommend that members use such devices in the treatment of SAD until further research has been carried out.



Reference Amanda Cross, 2007. SADA Science and Technical Officer.



For the full article and more information please see our website: Britebox SAD Light box