Light at Night

Light at Night

Look for third-party certification and optimization programs to avoid blue light at the wrong time of day

A walk down the light bulb aisle at your local big box store will raise more questions than it answers.

The point-of-purchase advertisements make a number of claims: “Natural Daylight,” “Sleep,” “White Light,” and more. But like a lot of advertising, it won’t raise the issue that lighting experts increasingly are trying to solve: Exposure to artificial light at nighttime has been shown to disrupt circadian rhythm, and has been associated with sleep disruption, cancer and other medical problems.Specifically, high levels of blue-rich light, characteristic of normal daylight, can be good for you in the morning. They suppress melatonin and increase production of alerting and mood-enhancing neurochemicals such as serotonin and cortisol, and generally help entrain your circadian clock.

But exposure to artificial light at night from standard LED (Light-Emitting Diode) or fluorescent light fixtures, your computer screen, television and other devices suppresses melatonin when your body needs it and delays deep, REM (Rapid Eye Movement) sleep.

“In the next few years, spectrally tuned LED lighting that automatically transitions from high-circadian content, bright light during the morning to dimmer, low-circadian content in the late afternoon and evening, will become more readily available, and will be a welcome improvement over the current-state-of-the-art,” says Scott Roos, vice president of design at Acuity Brands Lighting, Inc., in Des Plaines, Illinois.

What do we do in the meantime?

Install or activate a circadian-light optimization program such as Nightshift or F. Lux on any phone, tablet or computer, Roos says.

“While not a perfect solution, certainly a dimmed screen with lower blue content in the evening is an improvement over not having it,” he says.

And be wary of claims made on bulb packages, and by some manufacturers who offer “spectrally tuned” LED lamps for use at night.

“Make sure they have third-party certified test results that validate a low MR (Melanopic Ratio), or better yet CS (Circadian Stimulus), and that they are dimmable,” he says. “The latest research tells us that the amount of light reaching the eye is more impactful as a circadian stimulus than the spectral content.” ©


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