How Should I Obtain a Light Box?
Substantial research and clinical experience indicate that exposure to bright light at 10,000 lux for 7 days per week for 30 minutes before 8 a.m. results in substantial improvement in SAD and sub-syndromal SAD for most patients. An individual seeking a light treatment device faces a significant issue: many devices on the market are too dim and too small to be useful treatment options. In 2019 we published a paper analyzing 24 devices: only 3 were equivalent to full-size research devices. Three additional devices were somewhat smaller and dimmer but met our criteria (we believe that such units should meet 3 criteria to be recognized as a suitable bright light box: 1. the device must produce at least 7,5000 lux at a reasonable distance (≥11 inches); 2. The device must produce at least 5,000 lux if the user’s head is moved 5 inches to the left, right, up, or down; 3. The unit must be rated as non-glaring by our volunteer panel, and the light emitting surface must not contain marked “hot spots” of greater intensity). Some devices are no longer available, and some devices have been replaced. We are now updating our webpages as of October 2022. Failure to be included in this listing does not indicate a product does not meet our specifications or is not an effective treatment for SAD.
Intensity of light is important because many experts believe there is a trade off between lux and duration: 30 minutes of exposure at 10,000 lux for is thought to be equivalent to 60 minutes at 5,000 lux or 120 minutes at 2,500 lux. We urge the consumer who is looking for efficient light treatment to pursue equipment and conditions of use that result in at least 7,000 lux of exposure.
The individual seeking light treatment has a number of choices. We most recommend purchase of a full-size unit such as the NorthStar 10,000 or the SunRay II shown below, and we recommend purchase with legs which elevate the unit. Some individuals maybe be satisfied with units that are somewhat smaller or dimmer, but still offer a true 10,000 lux treatment. These include the BOXelite, the Day-Light Sky, the SunTouch Plus, or the BuddyLux below. There may be other treatment devices which would meet the specifications above but have not been tested by us.
Unfortunately, anyone looking online for a light treatment device for SAD will see many devices advertised as 10,000 lux, without specifying the distance at which this intensity is obtained. One major manufacturer sells a device that is 10,000 lux at a distance of 6 inches: obviously this is not a feasible approach to accessing this intensity of light for 30 minutes. Advertisements frequently show individuals using light devices at great distances, and often the user is not even facing the light. Fortunately, consumers now can check out device properties themselves. Cell phone apps for both iPhone and Android allow lux measurement with the front facing camera. Our tests indicate these apps are quite accurate. Users can verify that they are receiving 7,000 to 10,000 lux of light. Shown here is the use of such an app:
For additional options in treatment besides light boxes, see our page Other Light Treatment Options. Beam-type devices are light, small, rechargeable light sources which must be precisely positioned to illuminate the eyes. Column-type devices have a compact footprint: the only such device currently sold uses green light (see below). Light visors contain LED light sources mounted on a headband: LED visors have never been tested in a controlled trial but are popular with some patients. Longer periods of daytime exposure to lower levels of light than 10,000 lux have been reported to help some patients. Dawn simulators are intended to duplicate summer sunrise. Substantial anecdotal evidence supports the use of tropical vacations as a treatment for SAD.
At this time, we do not recommend treatment with blue light. Much research has shown that light from the short wavelength end of the spectrum, the blue end, has the strongest effect on the circadian rhythm system. This is likely related to the fact melanopsin is the pigment in the retina which transduces much of the effect of light on the body’s clock. Blue light is absorbed by melanopsin, but blue light is also most toxic to the retina. Green light affects melanopsin strongly and should be safer for the eye. Unfortunately, there has been little research on green light as a treatment for SAD. Few devices emitting green light are available for those who wish to try this approach, which should be regarded as experimental at this time.
We argue that any reputable company should provide clear specifications regarding the distance at which the device produces 10,000 lux. We also argue that the manufacturer should offer at least a 2-month trial period. Four weeks should be long enough to determine if the therapy will work for you, so you can return the device if you are not satisfied with it.
Manufacturers: if you have a device which you believe should be listed on this webpage as a research-proven approach to SAD treatment, please contact us regarding testing your device email@example.com.
Large Light Boxes
Multiple research studies support the use of large light boxes in SAD. These contain fluorescent tubes and emit white-appearing light. They should be used at the distance recommended by the manufacturer to obtain 10,000 lux of intensity. The following devices currently on the market appear to resemble adequately the devices used in research.
This is a large light box, with a light-emitting area measuring 21 1/2“ wide and 11“ tall. According to the manufacturer, it produces 10,000 lux at 24” (close to value verified in our tests). We recommend purchasing the legs, as these allow more convenient use on a table or counter. This device is identified as Device X3 in one of our publications. Ruler is 12 inches in length.
SunRay II ®
This is also a large light box, slightly larger than the unit above, with a light-emitting area of 22“ x 12 1/2“. According to the manufacturer, it produces 10,000 lux at 23“ (close to value found in our tests). This unit as sold includes the legs. This device is identified as Device X1 in one of our publications.
Day-Light Classic (DL930)
This is a somewhat smaller device than the above two devices, with the illuminating section measuring about 16“ by 13“. It is also less bright, but because of its design with tall legs the user can easily sit close enough to get 10,000 lux. It produced 10,900 lux at 12” in our tests. It is Device X4 in one of our publications.
This device does not appear to be currently manufactured. We recently tested a device termed the Day-Light Classic Plus from this manufacturer. It produced 10,000 lux at 13”. The light emitting area was approximately 13 x 15”. The Classic Plus appears to continue to be available from various sellers, but not from the manufacturer’s website.
See a somewhat smaller unit from Carex in the next section.
Smaller Light Boxes
In our tests several smaller light boxes appeared to meet the specifications described above. The user will need to sit closer and may not be able to move as much side-to-side. Some users may feel that the decrease in convenience would be offset by the more compact size of the device. There are many small light boxes advertised online which did not meet our specifications. For example, one small light box was advertised as 10,000 lux: in our tests it did so at 7”, which is not realistic for use.
The illuminated area of this device measures 15“ by 12“. The device produced 7,000 lux at approximately 16“ in our tests. The unit includes legs which elevate the device conveniently. The device is labelled as Device X5 in one of our publications.
This device now appears to be termed the BOXelite OS on the manufacturer’s website.
Day-Light Sky (DL2000)
This is also a smaller device, with a light-emitting area of around 13” x 10”. In our tests it produced 11,000 lux at a distance of 12“. It is built like a desk lamp and could be used as such. It is Device X6 in one of our publications.
SunTouch Plus ®
This is also a smaller device. In our tests the device produced about 10,000 lux at 14”. Users must position themselves carefully to receive 10,000 lux of exposure. It is identified as X11 in one of our publications. The device also contains a negative ion generator which can be used if desired: limited research has been done on the safety and effectiveness of this type of treatment and we have no recommendations for or against this such therapy.
Nature Bright Company, 5251 California Ave Suite 130 Irvine, CA 92617, USA
NatureBright also offers this large light panel. In our tests, it produced 10,000 lux at 11” and 7,000 lux at nearly 16”, so the user must position the device carefully to be exposed to this degree of intensity. The light emitting surface measures approximately 21 ½” square, so the user can move about and still obtain this intensity. This device was not studied in our published paper as it was not marketed at the time.
Nature Bright Company, 5251 California Ave Suite 130 Irvine, CA 92617, USA