Winter Blues?

The Right Lights Can Brighten Your Mood

SAD Lighting

It goes by many names. Seasonal Adjustment Disorder, Seasonal Affective Disorder and SAD syndrome. But you probably know it by just one: the winter blues.

No matter how cheerful and even-keeled we may be throughout the year, studies show that all animals human and otherwise react to the onset of winter and loss of light both physiologically and psychologically. While some of us may simply sleep more or suddenly develop an uncontrollable craving for chocolate, up to 20 percent of Americans suffer greatly from a serious form of depression doctors call "SAD."

Typical symptoms of SAD include oversleeping, overeating (especially sweets), depression, lethargy, stomach and joint pain, and lowered immune system function. Women are particularly susceptible to SAD, comprising 70-80 percent of those affected, and not surprisingly the incidence rate of severe cases rises dramatically the further one is from the equator.

Natural Light and SAD

Though the causes of SAD are not completely understood, researchers agree that light plays a vital role. Just as with plants, human beings wither without it. Studies show that light deprivation alters brain chemistry, triggering over-production of melatonin, which causes fatigue (in fact, many people use melatonin as a sleep aid).

Because 70 percent of our sensory receptors are in our eyes, visual stimulation and exposure to light are critical to well-being. Based on that fact, researchers hypothesized that by increasing the amount of natural light SAD patients are exposed to daily a process called photo- or bright light therapy symptoms would decrease. And they were right.

In 1984 a breakthrough study conducted by Dr. Norman Rosenthal concluded that bright light therapy minimized the effects of SAD. Though other treatments have proven useful in combating the illness, including daily outdoor exercise and prescription mood enhancers such as Paxil® and Zoloft®, photo therapy has become the preferred treatment method because it can be administered in any weather conditions, it is relatively inexpensive, and it is non-addictive.

Daylight Indoors

Increasing the amount of natural daylight indoors has a positive effect on preventing and combating SAD symptoms and has been shown to increase workplace productivity. According to a study by the Lighting Research Center at the Rensselaer Polytechnic Institute in New York, daylight does have a greater probability of maximizing visual performance than most forms of electric lighting because it tends to be delivered in large amounts and has excellent color rendering qualities. The research also indicates that daylight strengthens sales in retail stores because it elevates buyers' moods.

Though there are some negative effects associated with increasing the amount of daylight in buildings including thermal discomfort (overheating), glare, loss of privacy, and higher construction costs the energy savings and positive effect on the human circadian rhythm (our internal body clock that is controlled by light and tells us when to sleep and when to wake) far outweigh any downsides. In fact, the trend toward green building, which includes increasing the amount of natural daylight, is not only environmentally sound but is vital to our health and well-being. As Nick Baker of the University of Cambridge reports, we are all inherently outdoor animals and need daylight indoors, in any form, in order to preserve our physical condition and sanity.

Natural Lighting's Broad Benefits

Some in the lighting industry were well ahead of the curve in understanding the health benefits of natural light. In 1956, Howard Scott founded Verilux® and invented a line of lighting products "refined to include the best of natural daylight without the unnecessary wavelengths." In 1989, after 40 years of research on "the remarkable effects natural light had on plants, animals and humans," Dr. John Ott and Fred Mendelsohn founded Environmental Lighting Concepts (parent of OTT-LITE), based on the idea of simulating natural light indoors. These developments revolutionized the lighting industry, enabling customers to enjoy the therapeutic benefits of sunlight when it is difficult or impossible to find it outdoors.

Natural light simulating products are commonly referred to as full spectrum lights, although balanced spectrum may be a more accurate term, as all white light sources are technically full spectrum. The full spectrum lights have a color temperature of between 5,000-6,500 degrees Kelvin and a Lux output of 10,000 (Kelvin is a measurement of heat, based on absolute zero; Lux is the metric unit of measure for illuminance of a surface). Studies show that optimal benefits of SAD lamps are derived at 10,000 Lux or 930 footcandles reaching the eye (typically 6 to 24 inches from the source depending on the fixture).

SAD Lights vs. Light Boxes

Commonly used in phototherapy to treat SAD patients, light boxes should not be confused with SAD lights. Full spectrum lighting (in deed, exposure to any light source) does provide health benefits but should not be considered a substitute for the light box therapy that doctors prescribe. What SAD lights can do is provide soothing, glare-free, balanced spectrum light that can improve the quality of illumination in a room.

Research indicates that using these lights not only elevates mood and produces a healthier living and working environment, but it may even alleviate some of the suffering attributed to Alzheimer's Disease and help create a positive learning environment in school classrooms. In a study conducted by the Netherlands Institute for Brain Research, researchers concluded that simulated sunlight diminished some of the symptoms of Alzheimer's Disease by creating a more calming indoor atmosphere. Similarly, Alberta Education's Policy and Planning Division found that natural lighting has a positive impact on the productivity and physical development of students. According to a study published in 1992, students who worked in classrooms illuminated with natural light providing higher levels of illumination grew taller, attended class more regularly and achieved higher scores on the Canadian Test of Basic Skills.

Find Your Smile, Save Your Eyes

While increasing the amount of natural daylight in your home or office is the best option, it is not always available. That is why several manufacturers, including OTT-LITE, Verilux® and Design Classics®, offer natural light-mimicking product lines that replicate its broad benefits. True color rendering -- revealing colors as they are seen in broad daylight, not tinged yellow or blue is a main advantage of full spectrum lighting. Eyestrain reduction is another, as Vision Saver® bulbs and similar products reduce glare to enable reading, computing and performing intensive tasks for longer periods of time. Research also indicates that indoor pets gain significantly from this type of light -- especially caged birds, which exhibit fewer behavior problems and experience less feather loss than those not exposed to it.

Used by jewelers, artists, the elderly and anyone who wants clear and soothing illumination, sunlight simulating products generate an abundance of positive results. While there is no amount of ordinary light that can replace the clarity or benefits you can get from natural light, the next best thing is simulated light," says Dr. Ott.

While most of us don't experience the extreme depression of SAD, we can all profit from exposure to light. Whether it's reading for long periods of time, working on a computer, doing needlework or simply resting after a long day, SAD lights improve the quality of everyday activities by increasing clarity and providing the health benefits of daylight indoors, in any setting. So, heed the experts' advice and experience natural indoor lighting today raise your spirits, save your eyes and see what you've been missing.

True Color Rendering and Light Bulbs

The Color Rendering Index (CRI) is a measure used by the lighting industry to indicate a bulb's ability to render colors. The sun produces full spectrum light and has a rating of 100 CRI; bulbs are measured against this standard, with CRIs of 90 to 100 being the best at simulating the quality of light produced by the sun.

The color temperature of a light source is another characteristic that describes the color of the light. All light is technically full spectrum but SAD lights produce balanced spectrum light that mimics daylight while removing the UV rays. Conventional electric light varies greatly in the spectrum it produces, depending upon what type of light it is, its color temperature, and its lumen output. Generally, the cooler the light, the more blue its cast is; the warmer the light, the more yellow its cast. Full spectrum bulbs are the best light sources for true color rendering because they burn at 5,000-10,000 degrees Kelvin the closest replication of sunlight that can be artificially produced.

Fluorescent and compact fluorescent light bulbs are available in color temperatures ranging from warm (2,700K) "incandescent-like" colors to very cool (6,500K) "daylight" colors. "Cool white" (4,100K) remains the most common fluorescent bulb color but neutral white (3,500K) is becoming popular for office and retail use. CFL produce less glare than incandescents, which have a color temperature range of 2,000 to 3,300K. LED lights also produce less glare, and halogen bulbs have excellent white light quality.

Exposure to any of these lights can produce health benefits. But color rendering is best by those that are CRI-rated 90-100 and burn at high temperatures, like the sun.

Healthy Living, Healthy Lighting

Simulated sunlight sources including natural daylight bulbs, eyestrain reduction reading lamps and VisionSaver® lights promote healthy living by providing calming, rejuvenating illumination. Destination Lighting carries a wide array of these products, from OTT-LITE's VisionSaver® light bulbs to eyestrain reduction floor and desk lamps designed for reading and crafting. The VisionSaver® bulb line renders colors very well while producing low heat, which means energy savings as well as cool, glare-free illumination a healthy and economical investment. Destination Lighting's online catalogue also includes the Design Classics line of daylight reading lamps, which feature flexible arms for added versatility and hi-lo switches that adjust light-appropriateness for various activities.

So, if you need something to brighten your mood this winter or you just want to give your eyes a well-deserved break, Destination Lighting has the natural lighting products perfect for you. For a complete selection, shop Full Spectrum Lighting.


  1. American Psychiatric Association,
  2. Family Doctor,
  3. Nature magazine, "Melatonin Sensitivity to Dim White Light in Affective Disorders."
  4. "Winter Blues." Norman Rosenthal, Guilford Press, 1993; "Seasonal Affective Disorder and Phototherapy." Norman Rosenthal, Ed., Guilford Press, 1989.
  5. "Bright Idea for Alzheimer's." BBC News, 7.24.98.
  6. "The Advantages of Full Specturm Lighting." Ambrose Paul Wasdyke, Jr.CEE News, 1.90.
  7. Verilux, Inc.
  8. OTT-LITE Technology