Sleep in the Deep Dark
There are many factors that preclude or interrupt sound sleep. But in the modern world, light is a major (but not much recognized) complicating factor.
Fact is, for all but about the last century of human existence people have slept in night-time environments that have no extraneous light. Without modern light sources (light bulbs, etc.) things were really dark when the sun went down. This natural night-time darkness induced and facilitated long, deep, REM-promoting sleep (at least in winter).
Not so, today. Light is virtually everywhere at night. Natural, deep, complete darkness is hard to find, even in most modern bedrooms, where extraneous light from street lamps and vehicles washes walls with low but sleep-complicating levels of light. Studies have indicated that even a little nightlight, casting enough light to allow the finding of the way to a bathroom at night actually disrupts or suppresses sleep.
I’ve done a good bit of research on the topic. Earlier, I was lucky to get 8 hrs of sleep, even when I went to bed early. Then, after reading research on the effects of low levels of extraneous light on both animals and humans, (as I do with many health issues), I began to experiment on myself.
First thing? Closed the door to my bedroom, so that no light from the hall would enter. I thought I was then sleeping in pitch black darkness. I did notice better, deeper, longer sleep. Extraneous light had, for many years, compromised my sleep.
Next, I noticed that light from the street at night was pouring into my bedroom. Tried, then, to more precisely close the drapes. Worked, sort of. Light was still leaking in.
Finally (and so wonderfully), I solved the problem. Today, I commonly sleep, very deeply and restfully for 8 to 10 hours each night. The problem? The sun. Here in Ohio, in the summer, it brightens the sky for more than 16 hours each day. Even with my drawn drapes, my bedroom brightens markedly around 6am (or earlier) in the summer. But, fixed that. Am now sleeping, as mentioned, soundly for 8 to 10 hours each night, summer or winter.
The solution? I wear a soft sleep mask. The night I started wearing this, I noticed the difference. The light from my radio/alarm clock next to my bed had been enough, even with my eyes closed, to keep my brain from entering full, deep sleep. There were no bedside lights of any kind until the last century. Sound, full, health-restoring sleep requires, prolonged, all-night deep darkness. Today, light is everywhere, however. Block it, with a sleep mask.
Here’s what the Harvard Medical School recommends:
Use heavy curtains, blackout shades, or an eye mask to block light, a powerful cue that tells the brain that it's time to wake up.