After 25 hours of research, including reading two books and five comprehensive studies on the subject and interviewing one of the scientists who first discovered seasonal affective disorder (SAD), we found we would use the Carex Day-Light Classic Plus lamp to treat our SAD symptoms.
If the Day-Light Classic Plus is unavailable, goes up in price, or you’re willing to pay more for an arguably more attractive lamp, try the Verilux HappyLight Deluxe 10,000-lux Sunshine Simulator. It has many of the same features as the Day-Light Classic Plus, including 10,000-lux light up to 14 inches away from its surface and a large 200-square-inch face. And, it’s completely UV-free. Unlike the Day-Light Classic Plus, the HappyLight is not adjustable by height and angle, though that makes it a less cumbersome light overall and much easier to set up out of the box. The HappyLight is also a much cooler white than our top pick, which you may not mind; we prefer the warmer hue of the Day-Light Classic Plus.
Disclaimer: This guide is not a replacement for an official diagnosis of SAD by a physician. While many of us would cop to a case of the blahs when the weather gets colder and the days longer, that’s far different from a clinical case of SAD, which should only be diagnosed and treated by a medical professional. (See below for more on these differences.) You should use a SAD lamp or light box only under medical supervision, as they are, in fact, medical devices. That said, if we were going to try one out, here’s what we’d buy.
A staff researcher and I looked at 40 SAD lamps and considered nine very closely, taking Amazon user reviews and ratings into account. I spent a weekend reading Winter Blues by SAD expert Dr. Norman E. Rosenthal and spoke at length with Dr. Alfred Lewy, one of the first doctors to report on SAD in 1980. I also read as many research papers as I could download from the last three decades.
Many people experience some emotional or physical changes with the arrival of new seasons, especially winter: your mood may swing, your eating habits might shift, and your energy levels may rise or fall. Some people are less able to cope with these changes. SAD is a seasonal pattern of major depressive episodes as diagnosed by a physician according to criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR)1 (We repeat: This diagnosis can only be made by a trained physician and should not be self-diagnosed.)
For most of us, these seasonal shifts in our moods and energy might be annoying, but they’re fairly simple to manage. In winter, you may even enjoy the chance to curl up by a fire or take a walk in the invigorating cold air. In short, you read Ethan Frome once and didn’t understand all the endless brooding.
Then there’s a second group—those who feel the weight of these changes in a more serious manner. Maybe the symptoms aren’t quite severe enough to seek a doctor’s opinion, but they certainly make it hard to get out of the house in winter. It’s what we sometimes informally call the winter blues. This group read Ethan Frome once and felt that finally, somebody else understood what winter was like for you.
A third group experiences these changes so severely that their lives are seriously disrupted. It’s this last group that we would typically describe as suffering from seasonal affective disorder. If you have true SAD, the cold months may feel like a physical exhaustion that will never end. To you, Ethan Frome is a cheery book about sledding compared to how you feel every winter morning.
It’s important to note that not everyone experiences their symptoms at the same time or in the same way. In Winter Blues, Rosenthal writes, “Just as the degree of seasonal difficulties may vary from one person to the next, so may the timing of the problem. For example, one person may begin to feel SAD symptoms in September, whereas another will feel well until after Christmas.”
Therapeutic light boxes are not the only available treatment for seasonal affective disorder. If you think you’re among the roughly six percent of US SAD sufferers, talk to your doctor to figure out your best course of treatment (which might include anything from more time outside to cognitive behavioral therapy or antidepressants).
For most people with only mild seasonal mood disorders (some 14 percent of the US population), the risk of using a therapy light is relatively minimal; eyestrain and headaches are the most commonly reported side effects. However, as New York Magazine reported in its 2016 article on SAD lamps, people with a history of clinical depression or bipolar disorder may suffer an exaggerated response while using a light box and should only consider this therapy in close consultation with a physician.
In 1980, Dr. Alfred Lewy published the finding that sufficiently intense artificial light suppressed humans’ nighttime production of melatonin—a hormone linked to the regulation of our sleep cycle. According to interviews with Lewy, prior to that moment, there was more or less uniform agreement among medical professionals that artificial light had little to no effect on our circadian rhythms. As it turned out, most experiments up to that moment hadn’t used lights bright enough to induce a measurable change in our melatonin or circadian physiology.
“[Dr. Robert] Sack and I realized that humans really don’t have seasonal rhythms like animals do, like breeding and hibernation and reproduction,” Lewy explained over the phone. “We proposed a ‘phase shift hypothesis’ that is still the leading hypothesis for how bright lights treat SAD, which is that in the winter, with the shorter days, most people’s circadian rhythms drift late with the later dawn: out of phase with their natural sleep-wake cycle. It’s like having jet lag for five months. With morning bright-light exposure, those rhythms are pushed back earlier, back into phase with their sleep.”
Today, “bright light therapy is recommended as the first-line option” for the treatment of SAD, according to a 2003 review in the journal Dialogues in Clinical Neuroscience. Far from being a fringe or “alternative” purported remedy for SAD, light therapy has been clinically shown to work to alleviate symptoms in over 60 studies in serious scientific publications.
There are a few important factors to consider when shopping for a SAD lamp to ensure you receive the full therapeutic benefits of the light. Since we are not qualified or equipped to test SAD lamps for efficacy, we focused instead on how easy they are to use and whether they meet their stated specs, like the number of lumens. We considered all the points below and selected our two top picks for hands-on comparison.
First, know that the FDA does not test, approve, or regulate light-box devices. As such, we do not recommend using them without a physician’s guidance. We based our picks on research, product specifications provided by manufacturers, customer feedback, and conversations with experts who study and prescribe these units.
A light box should deliver between 2,500 and 10,000 lux. Lux is a unit of that measures one lumen per square meter. The more lux a light delivers, the less time you need to spend sitting in front of it. For most 10,000-lux lights, 30 uninterrupted minutes should suffice. (You could go longer, but for some people, that can cause side effects such as eyestrain and headaches.)
We also looked at how close you have to sit to each box to score the maximum results. Light intensity is subject to the inverse-square law, which says that the intensity of light falls off by the square of the distance that you move away from it. For instance if you are two feet away from a light source, you see a fourfold decrease in intensity. “I insist, absolutely, that any reputable, reliable manufacturer has to tell the consumer what the distance it should be from the eyes to achieve 10,000 lux,” said Lewy. “If a light box doesn’t have that information, I wouldn’t use it.” (If you’re prepared to drop nearly $400 or more, you can sit up to 20 inches away from the box, but we didn’t think it was worth paying three times the price of our picks to gain six to eight more inches.)
The larger the surface of the light box, the better. In Winter Blues, Dr. Rosenthal notes that the lights “used in almost all research studies…have an illuminated surface that is at least about one foot square.” For that reason, and the fact that smaller therapeutic lamps have not undergone the same kind of rigorous study that their bigger cousins have received, we strongly recommend light boxes with the largest surfaces.
Be sure to look for safe light wavelengths. “My recommendation is cool white fluorescent lights in a light box protected by a Plexiglass diffuser that absorbs ultraviolet radiation,” Dr. Lewy advised. Ultraviolet (UV) waves are potentially harmful to the eye and do not seem to be effective in alleviating symptoms of SAD.
While many SAD lamps fit the above specifications, we discounted many of them because of their high price for most people, overly cumbersome design, too-small size, or dubious claims to features like “ion therapy.”
We also avoided models that use blue LEDs, as there’s still controversy over whether blue light (which is different from blue-enriched white light) is harmful to the eyes. However, we’ll watch as LED technology improves and becomes less expensive.
Lastly, avoid incandescent bulbs. Though they’re fine for use in dawn simulators, they can build up a lot of heat near the eye in a SAD light therapy box.
The Day-Light Classic Plus by Carex projects 10,000 lux of 99.3 percent UV-free light from its 204-square inch surface, the minimum lux that any SAD lamp needs to be therapeutically effective according to the doctors we interviewed. The Day-Light lamp face mounts to a weighted horseshoe base by an adjustable arm. This arm allows the lamp’s angle and vertical position to be adjusted, reducing overall glare and increasing the flexibility of where and how you can use the lamp. For instance, you can set-up the Day-Light Classic in such a way that it allows you to read a book beneath it while keeping most of your face positioned well within the therapeutic 12-inch range of the lamp face. By comparison, to read in front of our runner-up pick, you would need to either place the book upright between you and the lamp, shielding you from some of the light, or lay it down in front of you, possibly extending you outside of its therapeutic range.
Fully extended, the Day-Light Classic is 28½ inches tall, while its lamp face is 15½ inches wide and roughly 9 inches deep. The lamp angle can swing approximately 65 degrees from fully to vertical to nearly horizontal. However, this design makes the entire lamp both harder to put together and more cumbersome to move around than our runner-up pick. The weighted base takes up a large 12-by-16-inch footprint by itself. But we think it’s worth it for the less expensive price, extended 5-year warranty, and the extra adjustability.
Compared to the cooler tone of our runner-up, the Classic Plus emits a pleasant, warm light. It’s gentler to sit in front of for an extended period, and the Day-Light’s light intensity can also be adjusted between a high (3 bulbs) and low (2 bulbs) setting. The Day-Light comes with a standard AWG 5 foot grounded power cord, which is interchangeable if it gets lost and plenty long enough for most people. However, this interchangeability means you can buy a longer AWG cord and use it instead, if you need to.
The Center for Environmental Therapeutics, a non-profit collective of scientists and clinicians dedicated to research and education about environmental therapies, recommends The Day-Light Classic Plus. According to the CET’s director of education, it’s the go-to light for many clinical trials that aim to study the effectiveness of light therapy. A recent New York Magazine guide also touted the Day-Light Classic Plus, and they quote psychiatrist Dr. James Phelps’s description of it as the “official research rig.”
The Day-Light Classic Plus is unwieldy and (some would argue) unattractive. If you don’t like the way it looks, you may prefer the more quiet design of the runner-up.
One perk of this upright design is that it’s meant to project light a bit further than adjustable units. The HappyLight reportedly extends its 10,000-lux light 14 inches away from its surface, a full 2 inches farther than our top pick. That’s not quite enough distance to compensate if you want to place a book or newspaper between you and the HappyLight, but it can be a pleasant amount of extra reach if you value a little extra personal space. Once set up, the HappyLight measures 20 inches tall, 13½ inches long, and 3½ inches wide. It doesn’t take up much more space than this when it’s leaning against its stand either.
Setting up and turning on the HappyLight couldn’t be simpler. It takes less than three minutes out of the box to have it turned on and positioned in your favorite spot. The HappyLight is also, after 20 minutes of operation, a bit cooler to the touch than our top pick. This difference in temperature wasn’t extreme enough to make it a real issue. It would probably be our top pick if it were easier to read in front of while keeping you positioned within its therapeutic range. It also comes with only a one-year warranty, compared to the five-year warranty of our top pick.
The Lightphoria, the current bestselling light box on Amazon, is too small to provide enough of an illuminated surface.
The Day-Light Sky by Carex is nearly identical to our runner-up. Both have a long neck and swivel head for custom positioning. However, this lamp has historically been more expensive than our top pick and hasn’t received the same expert recommendation.
The Aura Light is one of many small SAD lamps on the market today. It’s less expensive than our small lamp pick but guaranteed 10,000 lux within only 6 inches.
The Boxelite by Northern Light Technology was in close competition with our top picks but is currently unavailable for purchase. The Travelite and Luxor, also by Northern Light Technology, were both dismissed for their price and lesser reviews, respectively.
Light-therapy devices that work differently from SAD lamps and aim to treat other health problems—such as trouble waking in the morning, which is what dawn simulators like the Philips Wake-Up Light purport to do—were also excluded.
(Photos by Caleigh Waldman.)