Happy Lamps

More About Happy Lamps for SAD

Do happy lamps work?

Yes, happy lamps are well-studied and have been shown to alleviate symptoms of seasonal depression, and research is encouraging that it may help with other types of depression. However, they only work if they meet three requirements:

1. They must emit enough bright light to reach your eyes (usually 10,000 lux at 16-24 inches is sufficient).

2. You must use it long enough and often enough, usually about 20-30 minutes, and every morning. (Consult with your doctor for the best length of time for you.)

3. It must not cause harm by emitting UV rays, which could damage your eyes.

When looking for a happy lamp, make sure you know how many lux it emits at what distance, and that it is UV-free.

Is it a SAD lamp or a happy lamp?

These are two words for the same thing. Confusingly, SAD stands for Seasonal Affective Disorder, but “SAD Lamp” has a negative sound to it. Because these lamps can make you happier, they’re more commonly referred to as happy lamps.

How much light exposure do I need from a happy lamp to help with depression?

The recommendation is 5,000 lux-hours per day— so that could mean an hour in front of a 5,000 lux lamp, or 30 minutes in front of a 10,000 lux lamp. This is why it’s OK if your happy lamp isn’t quite 10,000 lux, or you don’t like sitting that close to it. You should just be aware that you may need to spend more time in front of it to achieve the same benefits.

What color of light or wavelength is most effective for treating symptoms of depression with a happy lamp?

Blue light is the most effective wavelength for a happy lamp to emit. This is because the protein in your eye that responds to light, melanopsin, is most sensitive to wavelengths around 480 nanometers, which is blue light (that mostly looks white to us). The intensity of the light matters more than this exact wavelength — so, the fact that the light is very bright is the most important part of an effective SAD lamp.

Can I use a bright regular light bulb instead of a SAD lamp?

No. Regular light bulbs do not generate enough light to be effective. A typical 60W light bulb would give you about 200 lux if you are sitting 24 inches away from it, whereas a happy lamp would give you 10,000 lux.

How do happy lamps work?

Happy lamps emit enough light that your eyes and brain interpret it as sunlight. The bright light sends a message to your brain to suppress melatonin, your “sleepy hormone,” so you start to feel more awake. And it’s not just melatonin— this early morning light sets your entire circadian rhythm for the day, which triggers the release of other hormones that control your blood pressure, bowel movements, hunger, and heart rate, all depending on the time of day.

Happy lamps can help decrease symptoms of depression, because the “winter blues” are thought to arise from a combination of circadian rhythm and hormone disruption

What is the difference between lumens and lux?

Lumens means the amount of light a source emits. Lux refers to how much light falls on a specific surface area. The conversion between the two is complex, but you can use an online lumens to lux calculator or type it into google to get a close-ish result.

Is CLA more accurate than lux?

No. CLA, or Circadian Light, is an interesting idea for a measurement that replaces lux. CLA, in theory, quantifies how effective light is on the photoreceptors in the eye, and how effective it actually is at shifting the circadian rhythm. But, it’s not yet a common or verified measurement, and there are very few scientific papers on it. I’ve mostly seen it as a marketing technique by a handful of brands, and while I think it’s a cool idea, it’s just not as informative as lux yet.

What controls circadian rhythm?

The number one controller of your body’s circadian rhythm is sunlight. This obviously got a little more complicated when humans made the leap to electric lighting after hundreds of thousands of years. And, in the hundred or so years since, we’ve added brighter, bluer lights, all over our homes, impacting our circadian rhythm in less natural ways, more and more. Moreover, in Northern and Southern hemispheres, we are often waking up before the sun rises. To keep a consistent year-long schedule, we can trick our circadian rhythm by using happy lamps and sunrise alarm clocks.

Is blue light bad for you?

Too much is. Excess blue light exposure is associated with insomnia, sleep disturbance, eye strain and macular degeneration, and incredibly, an increased risk of breast and prostate cancer. However, natural blue light is necessary in the mornings and day time and is a natural part of the spectrum from the sun. Exposure to bright, blue light in the morning improves sleep, mood, and alertness.

What do the Ks mean on happy lamps?

K stands for Kelvin, and is a measure of how “warm” or “cool” the light coming from the bulb looks. The Kelvin scale doesn’t match up perfectly with the wavelength scale, but in general, the higher the Kelvin number (like 6,000 K) the cooler and bluer light a light bulb emits. Low Kelvin numbers, like 2,100 K, mean a light bulb emits warm, amber colored light. In the morning, when you should be using your happy lamp for optimal results, using a high Kelvin, blue light, is most effective.