The Circadian Lighting association Code of Practice includes the following:

• Customer trials. CLA companies offer 30 day a no-questions-asked refund policy so that customers have time to determine for themselves that the product is helpful to them.
• Intensity claims. CLA companies will submit products to independent labs for intensity and UV measurements using a standardized measurement procedure.
• Safety and quality procedures. CLA members follow relevant safety and quality regulations and requirements.

News and concerns

Blue light
CLA companies believe it is premature and possibly unsafe to recommend monochromatic blue light therapy devices. Moreover, there is no need to take unnecessary risks, especially since blue light has not proven more effective for SAD treatment than more natural, broad spectrum white light. As Dr. Norman Rosenthal notes in his trail-blazing book 'Winter Blues' (2006 Edition):

"At the writing of this book, there is not one published study on the effctiveness of blue light for treating SAD. Nor is there a long track record of safety. On the contrary, there is long-standing concern about potential toxicity of blue light to the eyes. the bottom-line answer is, at this time stay with convential white-light fixtures."

Drs. Michael Terman and Jiuan Su Terman reach similar conclusions in a review article Ocular Safety, in CMS Spectrums (August 2005):

"Potentially damaging wavelengths above the UV range extend into the visible range up to 500nm (blue light). Alarmingly, one already sees manufacturers promoting blue light without considering that the interaction of blue with longer wavelengths in the white-light spectrum may be important both for efficacy and safety. At present, we recommend maintaining broad-spectrum white illumination."

20 minute treatment times
The CLA has noticed that claims have begun to appear regarding 20 minute treatment times for 15,000 lux lightboxes. We are not aware of any substantiating research and therefore assume that this figure is a simple extrapolation from the 30 minutes/10,000 lux accepted industry standard. Without further research to show this shorter treatment time is equally effective, we feel such claims are misleading and unjustified and we do not support the marketing of products in this manner.

Choosing the right light therapy product

As interest in the field of light therapy has grown, so has the industry that supplies specialty lighting products. There are now more products to choose from than ever. Finding the right product for you can get confusing, but it isn't that hard to master if you shop carefully and follow some basic buying guidelines.

Which product is best?

No single product is best for everyone, so carefully consider your own needs and the advantages of each product to decide which is best for you. Start by learning about the four basic lighting technology categories that are available today:

Bright lights - Light boxes are rectangular fixtures that house several fluorescent tubes. They have been around for about 10 years and have proven very effective. Light boxes come in different sizes and styles. Most experts feel that a 10,000 lux box is best, but smaller 5,000 lux light boxes can work too, although they require more time to be beneficial.

The light visor is a head-mounted light source that looks something like a tennis visor. The visor is designed to give people mobility during light sessions and portability for travel situations. The visor has been on the market for 6 years, and has also proven very effective for many people. Because of its efficient design, it requires only 3,000 lux to produce benefits comparable to a 10,000 lux light box.

Dawn simulators- Dawn simulators, the newest light technology, mimic a natural sun rise, gradually brightening a room over a set period of time. Some can also produce an artificial sunset. They appear to help people wake up more easily in the winter, and studies indicate that they may have therapeutic value as well. Many people use them as a supplement to a bright light program.

Each technology has pros and cons that you need to evaluate in the context of your own unique situation. For example, if getting started in the morning is your main challenge, you may do well with a dawn simulator. A light box may be best if you like a regular routine, or would like to use something while you're at a desk or computer. And the visor is a good choice if you need mobility or you like to travel. Think carefully about your needs and consult a heath care professional to get guidance on your choice.

Where to buy light therapy products?

It is important to choose a reputable company that can provide a quality product at a good price, with reliable service over the long term. Consumers can have confidence in companies who are members of the industry trade group, the Circadian Lighting Association (CLA) because all CLA member companies:

Buying guidelines

1. Is the company a member of the Circadian Lighting Association?
2. What specific products do you recommend for me? (describe your situation)
3. Do you have a 30 day money back guarantee program? (stop here if the answer is no)
4. Does the product filter out UV? (many experts feel UV may be unsafe)
5. Has this product been tested for effectiveness in clinical trials?
6. What is its lux output at what distance? (ask for output levels at a realistic usage distance, say 50cm or about arm's length)
7. Has the product been tested by an independent test facility? Is it UL approved?
8. What is the warranty coverage? (a warranty of at least one year is a must)
9. How big is it? (size and weight)
10. How much does it cost? How much for shipping? Cost of replacement bulbs? Extra costs for accessories etc.?

This information was provided by the Circadian Lighting Association. For more information about quality lighting products, contact the Circadian Lighting Association member companies.

Other good places to go:
The Society for Light Treatment and Biological Rhythms (research group) www.sltbr.org
United States National Association for Seasonal Affective Disorder (NOSAD) www.nosad.org

Updated 26 August 2008