Well-lit rooms full of natural light are not just aesthetically pleasing, they contribute to our overall health.
The body’s natural circadian rhythms rely on full-spectrum light exposure to set our internal clocks, and anticipate daily changes in our environment. According to postdoc fellow Annika Barber, “light is our biggest time cue, but blue light is particularly important.”
Natural light consists of several wavelengths. Blue wavelengths specifically trigger cells in our eyes that transmit information to the part of our brains that control our circadian rhythms. Bodies that lack access to natural light can suffer from metabolic sluggishness. Conversely, excessive exposure to fluorescent light sends artificial blue lightwaves to our brains at times of the day when we naturally taper off our exposure to light. This is why it is wise to limit exposure to devices and screens before bedtime, so the body's natural circadian rhythms are restored.
For people who lack regular access to natural light during the day, there are tools to replicate full-spectrum light sources. However, Barber warns that the timing is just as important when using these light alternatives. “You don’t want to be telling your internal clock that it’s morning at 3:30 in the afternoon,” she said. “The body will take this as a wake-up call—but at the wrong time!”