Light Therapy - Facts and Tips

Why do we feel so rejuvenated on a bright sunny day? Because light actually produces hormones and neurotransmitters that affect our mood and well-being. However, natural sunlight levels are often unpredictable due to weather, latitude or terrain, and isn’t always available when needed, such as early in the morning or in the evening.

In the early 1980’s, researchers discovered that specialized bright light was an effective treatment for ‘winter blues’ or seasonal affective disorder (SAD). Now tests are confirming that this light is also effective for many other disorders such as:

• Clinical depression (non-seasonal)
• Depression in pregnancy and postpartum depression
• Bulimia nervosa
• Premenstrual syndrome (PMS)
• Restless sleep and daytime agitation in dementia and Alzheimer’s disease
• Sleep disorders such as those associated with shift work and jet lag, and circadian sleep disorders including Delayed Sleep Phase Syndrome (DSPS), and Advanced Sleep Phase Syndrome (ASPS)

Studies confirm that, not only is light as effective as other methods, but it causes no long-term side effects. Additionally, people responded within a week to light instead of several weeks with medications.

Light therapy or bright light treatment involves the use of a special type of light fixture that produces much brighter light than regular indoor lighting. Light therapy consists of the daily administration of artificial bright light of appropriate intensity, duration, and time of use.

The intensity of the light is given in lux. Lux is measured at a specific distance away from a light source; for light therapy devices, this specific distance is at the user’s eyes. To be effective, light therapy requires a minimum of 2,500 lux. However, the brightness recommended by researchers for most people is 10,000 lux, an amount which is significantly higher than standard indoor lighting. While daylight is almost always at least 10,000 lux, most homes have light levels between 100-300 lux, and well-lit offices generally don’t go above 700 lux.

The light box is considered the best light for bright light therapy. These are metal fixtures that contain white fluorescent light bulbs behind a diffuser, which spreads the light evenly over the surface of the unit and absorbs and filters out the potentially harmful UV rays. The light box should be tilted forward so that the light is angled downward, permitting more light to enter the eyes and decreasing the apparent brightness and glare of the light. These boxes are available in a large variety, including large models on floor stands for use with exercise equipment, compact models for frequent travel, and models designed to fit into office décor.

A newer technology is the head-mounted Light visor, which allows the user more freedom of movement while still receiving light treatment. However, the jury is still out on this one, and researchers have yet to determine whether it is an active treatment or whether it acts as a placebo.

Bright light treatment is generally well tolerated by most people. Side effects, when they do occur, most commonly include headaches, eye strain, nausea, dizziness, and feeling wired.

However, certain people should be carefully monitored when using light treatment. Those who have preexisting eye abnormalities, such as macular degeneration or retinitis pigmentosa, people with systemic illnesses that affect the retina, those who have had cataract surgery, and those taking certain photosensitizing medications, should begin light treatment only with routine ophthalmologic examinations and with careful consideration of the risks and benefits.

If you are considering purchasing a product for bright light therapy, remember that this is something you will likely use on a daily basis, either year-around or for a significant part of the year, and for many years to come. You will want to choose a product that is as comfortable for you to use as possible, as well as two other important issues: safety and effectiveness.

When considering the product’s safety, make sure it is free of UV wavelengths, that it has a proper diffusing screen and that it is UL listed.

When evaluating the product’s effectiveness, make sure it has been clinically tested, that it provides 10,000 lux of light, that it delivers the light in a downward angle and that the light is diffused evenly over the entire surface of the lamp.