More than fifteen hundred of you have read our blog post, Light Therapy Good: Bunkum Bad, where we observed, with some distress, “To be competitive, each [company has] to offer something to distinguish their product from others. One way [is] to make it less expensive. And one obvious way to do that [is] to skip costly controlled clinical trials. Manufacturers of antidepressants and sleeping pills are legally and ethically required to conduct such tests, but a light box is not considered a medication, and is free of such requirements.”

Innovative technology proceeds apace, with companies including General Electric, Philips, Osram, Tabu, and LightingScience in the race.  One LED manufacturer is now selling a lamp that “keeps people pumped up by pumping up the blue.” Terry McGowan, an official of the American Lighting Association, puts it well in a New York Times Gadgetwise feature: “You have to start thinking of light as a drug.”

But how prudent would it be to start taking a new drug simply because the ads claim it works miracles?  Despite the aggressive promotion, it would never get to market in the first place without FDA evaluation and approval.  Even then, FDA would be on the lookout for exaggerated claims for the drug’s effects on body function.

What the media more wisely should report is scientific information about a lighting device’s effects, side effects, and comparisons with existing devices with a proven record.  This could be an important step for nonpartisan consumer organizations to take.  There is an important lesson to be learned from psychopharmacology.  When classic meds go generic, and become less expensive for consumers but less profitable for Big Pharma, the response is often to introduce and heavily market new medications that cost a lot more, but are often no more effective than the older, cheaper formulations.

Let us be clear here: Recent research shows that blue light indeed has very specific effects on our neurochemistry. There are specialized ganglia in the retina of the eye that contain a substance called melanopsin that is specifically sensitive to light in the blue part of the visual spectrum. These ganglia communicate directly to the structure in the brain that is the seat of the inner clock. Such neuronal stimulation in turn has profound influence on mood, energy level, and the sleep-wake cycle.  There are specific times of day when you want to stimulate melanopsin with enhanced blue exposure—often in the morning to help you wake up in time, but sometimes in the evening as well, if you are falling asleep too early.

So suppose you’re on deadline and starting to feel drowsy. Or it’s mid-February and you’re in that emotional slump you’ve come to expect at this time of year. Why not run out and buy one of those blue-light gadgets and start treating your problem?

Here are some reasons you should think twice about doing that.

  • You will likely spend more than necessary on the latest bulbs or fixtures. While it is true that light in the blue part of the spectrum affects the inner clock, research has shown that ordinary white light—in the range of “soft white” to “daylight” (3000-5000 Kelvin in color temperature)—has more than enough blue in it to do the job (technical analysis here).  Furthermore, dim, gradual dawn simulation in the bedroom, for example, has the same capability of adjusting the inner clock for better sleep, and providing an antidepressant response, as bright illumination.
  • Many people find intense blue light quite uncomfortable, something like having a car with those high-intensity headlights coming at you. And face it: people are more likely to skip a treatment that makes them uncomfortable.
  • Bright-light therapy for mood and sleep problems depends on the correct intensity and timing of the light exposure, and these differ from one person to the next. Sit in front of a therapeutic light box at the wrong time of day for you, and it may have exactly the opposite effect than the one you are hoping for.
  • It is also possible for blue light, in combination with various prescription drugs, to cause a photosensitizing reaction and damage the skin or retina.
  • More generally, decades of scientific research on bright-light effects have shown that the size, positioning, and intensity of a light bulb or lighting device all matter. A company whose business is making and selling LED lamps may not get these characteristics right. We have not yet seen the results of clinical and field testing. It is not just a question of getting pumped up by pumping up the blue, or making other changes in the light provided.

Here are some of the new, and some of the proven:

New, and not yet fully tested for efficacy and safety


Awake and Alert, from LightingScience.

Awake and Alert, from LightingScience. Two versions of the bulb are intended to either enhance or dampen blue-light exposure.

GoLight from Philips.  Blue LEDs for activation, in a small-field configuration.

GoLight from Philips. Blue LEDs for activation, in a small-field configuration. Definitive clinical trials still pending.

Tested and proven


Uplift Daylight Classic, Model 930.  Used extensively in published clinical tria

Uplift Daylight Classic, Model 930. Used extensively in published clinical trials.

LowBlueLights glasses and lamps.  Eliminates the entire blue range of melanopsin

LowBlueLights glasses and lamps. Eliminates the entire blue range of melanopsin stimulation,

f.lux computer/iPad/iPhone screen controller (free download).

f.lux computer/iPad/iPhone screen controller (free download). Shifts the bright-white screen to a softer color at night.

...and an interesting merger of LEDs with timed shifts in color temperature (for heightened and diminished blue), providing dusk-to-dawn simulation in the bedroom:

LED lamp programmed to vary in color temperature across the day and night.

Per2 LED lamp programmed to vary in color temperature across the day and night.

Sources for the four items above:

  1. Uplift Daylight Classic, Model 930
  2. LowBlueLights glasses and lamps
  3. f.lux dynamic screen controller
  4. Per2 LED dusk-to-dawn lamp


We end our post by quoting one recent commercial ad:

  • We make the only biologically corrected light bulb.
  • We can support your body’s natural circadian rhythm and help you get to sleep.
  • We can promote natural alertness without stimulants or pills.
  • And we work with nature, not against it.

Items 2-4 are right on target, but Item 1 would legitimately be questioned by competitors.


Michael and Ian co-authored the 2013 Penguin paperback, Reset Your Inner Clock. They invite you to follow them on Twitter for news updates, opinions, and challenging Q-and-A’s. If you want to stay on top of body-clock matters, light therapy, and more — and take advantage of confidential, online self-assessments of inner clock time, depression, and seasonality — you should become part of the nonprofit Center for Environmental Therapeutics community. Email so we can stay in contact.

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