About 15 years ago, scientists began to investigate a new photoreceptor in the eye called melanopsin. It’s sensitive to blue light in the narrow 460–480 nanometer range and impacts our brain performance as well as our sleep.
What’s so special about blue light? A lot, it turns out. Exposure to blue light during waking hours makes us alert and productive, while exposure at night puts us at risk for sleep disorders — not to mention a groggy morning.
Blue light is all around us — in white light, in the glow of electronics, in fluorescent bulbs, in sunlight — and doesn’t go away at night in our modern lifestyle.
Here’s how to make the color or light work for you, not against you.
Blue light supercharges us during the daytime
Blue-enriched light can actually improve alertness and your performance at work during the daytime. One study exposed white-collar office workers to both white light and blue-enriched white light. Those who worked under blue-enriched white light showed improved work performance, more alertness, less irritability, less difficulty focusing, less difficulty concentrating, and less blurred vision.
And, these workers also reported a better quality of sleep at night.
Sleep disruption: the dark side of light
Unfortunately, today’s lifestyle keeps the lights on well past the sunset, which disrupts our sleep patterns.
Light, especially blue light, suppresses melatonin production, the hormone that regulates our sleep cycle. This is why sleep hygiene experts and sleep researchers recommend we dim our lights at night and avoid using our phones and laptops before bed. Electronic devices, energy-efficient light bulbs, and other common light sources all emit blue light in high concentrations. A couple hours of simply reading on a tablet before bed can delay sleep (study).
Unfortunately, without a good night’s rest we’re at risk for lower brain performance in many areas, including decision-making and learning. (Learn more about how to use sleep to our brain’s advantage.)
How to manipulate light for better productivity and brain performance
During the day, expose yourself to blue light. Work in a well-lit room and spend time outside in the sunlight. If you live in an area where this is difficult, get a sunlight lamp.
Once the sun sets, switch blue light for orange/red light.
Use dim, amber-colored night lights in your hallway, bathroom, and bedroom, eliminating the need to turn on bright artificial lights in the evening.
And of course, don’t use electronics before bed. If you must use your laptop, download f.lux, which reduces the amount of blue light in your computer screen when the sun sets in your hometown, leaving the redder lights behind so that you can still use your laptop.
If you want to be active in the evenings, you can try a clever sleep hack: blue-blocking glasses. Wearing amber-colored shades for one to three hours before going to bed lets your body produce melatonin as if it were dark, even if you’re using electronics or reading in a well-lit room (study).
You may even sleep like a baby. One two-week study showed that wearing blue-blocking glasses for three hours before bedtime gave participants a better night’s’ sleep and significantly improved their moods the next day (study).