Light therapy has long been used to attempt to help people with both mental and physical challenges.

SAD lamps are now in common use to treat depression and studies have shown that blue enriched light can be used at a lower level of intensity than white light alone.

Blue light often gets a bad reputation for being harmful though.

And this is a valid concern but as with anything like this.., it is the amount of a substance or sound or light that is the contributing factor in what effect it has.

We need all bands of the light spectrum to receive its full benefits.

This study sought to test two particular wavelengths of light, blue and green.., to see if effects were measurable and similar across multiple people with regards to effecting a more instant sense of emotion.

These two colours were chosen because they use different neural pathways to process the information.

And the exposure to the light was just a few seconds and not the hour long sessions that are often recommended by practitioners of light therapy.

The experiment used an angry or neutral voice as the trigger for an emotional response.

Interestingly, the response was higher (more negatively emotional) with blue light than green.., indicating that the different processes by which the two wavelengths get processed in the brain also result in different amounts of reaction and response.

And of course how we react to something emotionally can lead particularly with repetition to longer lasting changes in our overall mood which is where SAD lamps came into use.

Creativity and innovation have also been attributed to being enhanced by this blue light. Is blue light therefore like an enhancement of emotional state regardless of what emotion is present?

In a similar experiment, red was compared to blue and found to be better at promoting focus and concentration compared to blue’s creativity and innovation.

So colour does make a difference.

It’s not just blue that deserves attention.

It’s important to understand of course that sunlight contains all of the blue light we need and that light timing is just as important as it alters circadian (internal body clock) rhythms.

So for example an excess of blue light in the evening can cause you to be too awake and cause problems with sleep.

Nature knows best with a sunrise and sunset time.

The effect of the blue light got less over time suggesting a habituation of that wavelength on emotional responses whereas the green light remained the same in effect.

So as with many of the recommendations for improved performance or mood.., what you input into the system will be enhanced by the system.

Crap in equals crap out.

Relying on a SAD lamp for example without doing the work to put your life on a better path forward may not have the preferred result.

And the speed of these responses in this and other studies show just how powerful light is.

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