The Sleep Experiment: Why I now sleep with a nightlight

I am normally what some might call "a good sleeper." I sleep fairly heavily and can sometimes sleep for a long time. If something (or someone) wakes me up, I can often fall back to sleep. And I almost never wake up in the middle of the night. Once I'm out, I'm out until morning.

Over the course of the first few nights in my new basement room, I found myself waking up in the middle of the night a lot, for no apparent reason. I'd check the clock then go back to sleep. This happened several times a night. (Probably anywhere from 2-5 times.) For me, this is strange behavior. I was plenty warm (thanks to a heated mattress pad and two heavy blankets), but not too warm. I wasn't having nightmares about forgetting to teach my class or going to my thesis defense unprepared. The house is quiet at night. I'd guess it was just getting used to a new place, but after a few days, I went on an overnight trip and slept on a couch in a basement and slept fine again.

As I puzzled over it, I decided it might have to do with the fact that my new room doesn't have any windows. None. Not even a small one. There are also not any windows in the rest of the basement. As a result, it's very dark, regardless of the time of day, and light doesn't even sneak in under the door.

Based on my experience in the first week of sleeping there and from countless nights of sleeping in dark observatory dormitories, I came up with a hypothesis. It is that your body requires light and especially light cycles (such as the rising and setting sun) to sleep properly. It makes you feel safe, and aids you in knowing when to wake up. Without light, your body doesn't know when it's supposed to be awake. (Think of it this way: your body wakes up thinking, "What time is it?" "Oh, okay, I can still sleep.")

I don't mean that you can only sleep when it's dark and will wake immediately with light. (Trust me, I sleep through sunrise quite routinely.) And of course there are other reasons why someone might suffer from insomnia. But for someone who is normally a "good sleeper," I mean that after sleeping for awhile, without light your body isn't sure if it's time to wake up yet or if it should keep sleeping. Often when I sleep in the very dark rooms at the observatory, I find myself waking up every couple of hours. I usually blame that on shifting my sleep schedule, as your body can get pretty messed up working all night and sleeping all day.

But in my window-less room, I was finding the same thing. I started hypothesizing about the role that light plays in one's sleep patterns after finding myself waking up several times each night. (If I worked in some kind of physiological science, I would totally do a formal study on this. I'd actually be surprised if people haven't already.)

So after a week or so, I began the experiment on myself, starting on a Sunday. The goal was to find out if light really does affect my sleeping patterns, and if it does, to figure out an arrangement that will allow me to sleep soundly through the night. Here's what I did, along with the results:

Sunday: My cell phone's front screen stays very dimly lit when it is plugged in. Normally I turn it over as I sleep because it bugs me. Tonight I left it turned up to give me a very slight amount of light as I slept. Result: I woke up fewer times, but still woke up a couple times. Adding light to my room does seem to work, but the cell phone front is too dim to produce desired results.

Monday: Left my cell phone flipped open all night on the dresser, so the light was slightly brighter. Result: I slept better. Hardly woke up in the night. However, I don't want to give my cell phone that kind of wear.

Tuesday: Bought a nightlight for 99 cents at Target. Plugged it in on the far side of my dresser, so it provided light, but not too much light. Result: I slept all night, except once or twice when I woke up because the nightlight was TOO bright.

Wednesday: Provided the nightlight with even more shading (from an open suitcase and an overflowing laundry basket). Result: Slept all night, but still woke up because the light was STILL too bright.

Thursday: Bought a plug timer from Walmart for $4. I plugged the nightlight into it. I set it to turn off 30 minutes after I went to bed and turn on 15 minutes before my alarm. Result: I slept through the entire night, waking up about 10 minutes after the light turned on and a few minutes before my alarm went off.

By this point I felt pretty confident in my theory and new set up. But I knew it would need to be further tested; I'd need to sleep a few days with no light again, then a few days with the timed nightlight. This would confirm whether or not the change in my sleep patterns are in fact related to lack of light cycles, or if it's something else. Like adjusting to sleeping in a new place.

Friday: Nightlight turned off before I was ready to go to sleep, so I went to sleep without, though it turned on the next morning. Result: I woke up several times in the night again.

Saturday/Sunday: Nightlight timing set. Result: I still found myself waking up a time or two in the night. Hmm....need to revise a bit.

Monday/Tuesday: Tried the timed nightlight as well as leaving my charging cell phone positioned so the very dim light shines all night. Result: I slept through the entirety of both nights.

This last set up (the timed nightlight and the dim light from the cell phone) is how I've slept every night since then, and I sleep great now.

Conclusion: Our bodies needs light and light cycles to sleep properly. This makes sense if you think of how humans functioned before electricity. The sun provided light cycles, and at night it is never truly dark: the moon and stars provide light. (I've been in enough of the darkest sites around the world to know that even in the remotest places far from the city lights, it is never ever TRULY "dark.") Light likely also provides some kind of "safety" feeling.

I am sleeping well again because I have simulated these light cycles with my nightlight. Every night I set my alarm, but I also set my nightlight (I have to set the time on both ends...when to turn off and when to turn on).