Have you ever made this mistake after dark?

As a grad student and in my first years as an assistant professor, I would sometimes get a great idea in the middle of the night, and spend a few hours typing away at the computer. Awesome for moving my work ahead, but I had a tough time sleeping soundly the next night.

With our first child, the worst part of a midnight diaper change was the brightness of the night light. I would feel awake for the next hour or so, making it really difficult to get a full night’s sleep.

And there’s something really delicious about (sometimes) staying up late to finish an absorbing book with a little book light. But leaving the lights on to read made it tricky to wind down afterwards!

It turns out that screens and regular lights–especially blue-tinted types like LED and florescent bulbs–mess up your body clock when used at night.

Why red is my favorite color at night

Did you know that red light is the only color in the spectrum that doesn’t change your circadian rhythms? Dr. Roseanne Armitage, Director of the Sleep and Chronophysiology Laboratory at the University of Michigan, explained this little-known fact to me a few years ago. I was a lucky participant in a sleep research study–one of the coolest things I’ve done.

Dr. Armitage urged me to set up my house so that I only exposed myself to red light or darkness during the night time hours. It’s one of the BEST pieces of advice that I’ve ever gotten. We’ve been doing so for a few years now.

Red light in the evening takes a little getting used to

It’s taken some experimentation, but we’ve outfit nearly every room in the house with a red light.  These days, we turn on the red lights and switch off the regular fixtures at the beginning of our nighttime routine (about 1 hour before we expect the kids to fall asleep). We avoid using screens after that time, too.

Red light at night is very soothing

With the cue of changing light levels and color, not to mention the musical alarms that announce PJ time and toothbrushing, the kids calm down for bed much more quickly.

Using red lights during any night wakings means that we go back to sleep faster. And we’re less likely to get into a wakeful pattern several nights in a row.

How will you change your lights in support of your body’s natural rhythms?

Update, December 2014: Visit my “Red Light Inspiration” board over at Pinterest. I’ve pinned lots of ideas for implementing Red Lights at Night!