Light therapy lamps began appearing around 1982. They were large, heavy, crude light boxes with huge bulbs. This market was flat until 2001, when sales began to pick up and grow about 10% per year. Litebook Co. entered the market around this time, answering an unmet market need—for smaller portable equipment that could be used at home as well as in the office or when traveling.

Public awareness about light therapy benefits is still not widespread. However, rather than sales being restricted to areas of the nation with less days of sunlight (i.e. Seattle), sales of light therapy “boxes” are made to ALL states. Since consumers are now more aware of the dangers of skin cancer and exposure to strong sun in southern states, they are spending more time indoors, to escape the heat and humidity.

There are four main players in this market: Phillips (via the acquisition of Apollo Health and subsequently, Respironics, The Wake Up Light-dawn simulator), The Sunbox Co.  (fluorescent bulb-based equipment), Verilux  (fluorescent bulb-based equipment), and The Litebook Co. There are many small mom & pop companies also in this business.

Description & Theory

According to Wikipedia, light therapy or phototherapy consists of exposure to daylight or to specific wavelengths of light using lasers, LEDs, fluorescent lamps, dichroic lamps or very bright, full-spectrum light, for a prescribed amount of time and, in some cases, at a specific time of day. It has proven effective in treating Acne vulgaris, seasonal affective disorder, and is part of the standard treatment regimen for delayed sleep phase syndrome. It has recently been shown effective in non-seasonal depression.

In the treatment of delayed sleep phase syndrome (DSPS), the timing of light exposure is critical. The light must be provided as soon after spontaneous awakening as possible to achieve the desired effect, as shown by the phase response curve for light in humans. Some users have reported success with lights that turn on shortly before awakening (dawn simulation).

Modern phototherapy lamps used in the treatment of seasonal affective disorder and delayed sleep-phase syndrome do not emit ultraviolet light and are considered safe and effective for the intended purpose, as long as photosensitizing drugs are not being taken at the same time and in the absence of any existing eye conditions. Light therapy is a mood altering treatment, and just as with drug treatments, there is a possibility of triggering a manic state from a depressive state, causing anxiety, and other side effects. While these side-effects are usually controllable, it is recommended that patients undertake light-therapy under the supervision of an experienced clinician, rather than attempting to self-medicate

Everyone's body produces the important hormone melatonin (the so-called sleep hormone). Increasing your body’s melatonin production can improve your sleep. Melatonin is produced by your pineal gland, normally only when you are in darkness. Using artificial light in the evening before going to bed shuts down melatonin production.

Only the blue component of light shuts down melatonin production.

Sleep lamp makers have glasses and lights with filters that eliminate only the blue component of light. Using them for 1-3 hours before bedtime allows melatonin to be produced naturally. While using them, the remaining colors of light allow you to read, watch television, etc.

Seasonal Affective Disorder (SAD)

Exposing the eyes to light in the morning has become the standard treatment for SAD. Seven years ago it was found that it is the blue rays that are most effective in suppressing melatonin and devices that only produce blue light are now available. It is still the blue rays from the white light sources that are producing the effect. This is not without some risk. The blue light is known to cause damage to the retina which ultimately may result in macular degeneration and partial blindness. The risk is small but not zero. The blue light damage is dependent on how many of the blue photons have arrived at the retina over a long period of time.

It is believed by some that the basic cause of SAD is the presence of melatonin in the blood which makes the individual feel sleepy and depressed. The successful treatment with blue light that causes suppression of melatonin supports this view.

This new treatment for SAD is completely free from the retinal hazard of blue light. It depends on advancing the melatonin cycle so that it finishes before the individual awakens. This is made possible by donning blue-blocking glasses in the early evening. After doing this regularly for several consecutive days, the melatonin cycle will be advanced in time.  Many studies have shown that the melatonin cycle will not last more than 9 or 10 hours even when no light is present to suppress it, e.g. blind people.  If the glasses are put on regularly at 9 P.M., the cycle will start by no later than 10 P.M. and finish no later than 8 A.M.

How to Choose A Good Light Therapy Device

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:

- Have been in business for at least five years

- Offer a 30 day, no-questions-asked money back guarantee

- Make products to the highest quality standards, proven by independent testing

- Meet or exceed international safety standards

- Support research and patient support organizations

- Understand the needs of people who need supplementary light and care

Buying Guidelines

According to the CLA, When you are considering buying a bright light product, do your home work, and ask questions. To learn more about bright light and "winter blues", consult a knowledgeable health professional and get some library books on the topic (Dr. Norman Rosenthal's Winter Blues is a good place to start). You can also contact the support group for SAD sufferers, the National Association for Seasonal Affective Disorder (NOSAD) at www.nosad.org. When you are ready to start talking to companies, request an information package and prepare a product comparison worksheet with answers to some of the following questions:

1. Is your 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 20 inches)
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? Bulb replacement cost? Extra costs for stands, cases, etc.?

Some Light Therapy Machine Manufacturers