Promoting the eye mask - it does wonders!
I am truly amazed at how much better I nap when I'm wearing an eye mask. It's as though I'm able to enter the deepest sleep possible within minutes of falling asleep, maximizing the two hours I allow each day to nap. Add with the satin pillowcase I blogged about a few days back, and I'm now sleeping better than ever.
Because my naps have been so darn good, particularly with the use of an eye mask, I decided to do a little research on why blocking out light yields such a good sleeping experience. Turns out there are websites galore that explain our sleeping patterns, the factors that impact our sleep, and specifically, how light affects how much rest we get. The links to two of the more informative sites are here and here - but I'll share a few snippets below:
HOW LIGHT AFFECTS SLEEP:
Sunlight detected by cells in the retina of the eye sends messages to the brain that keep us in a roughly 24-hour pattern. These light cues trigger all kinds of chemical events in the body, causing changes in our physiology and behavior. For example, as evening approaches and the light in our environment dwindles, the hormone melatonin begins to rise and body temperature falls—both of which help us to become less alert and more likely to welcome sleep. With the help of morning light, melatonin levels are low, body temperature begins to rise, and other chemical shifts, such as an uptick in the activating hormone cortisol, occur to help us feel alert and ready for the day.
Scientists refer to sleep drive as a homeostatic system. Like body temperature or blood sugar, sleep is regulated internally. For instance, when body temperature falls, blood vessels constrict and we shiver; when blood sugar levels rise, the pancreas secretes insulin; and when we remain awake for an extended period of time, structures in the brain promote sleep. Furthermore, the duration and depth of our sleep vary according to the quantity and quality of sleep obtained previously. With every waking hour there is a strengthening of the homeostatic sleep drive. This strengthening isn’t directly measurable as a quantity, but experts think that it is the result of the level of brain activity during wakefulness. One hypothesis suggests that the build-up in the brain of adenosine, a by-product of energy consumption by cells, promotes sleep drive. The fact that both adenosine and sleep drive increase during wakefulness and dissipate during sleep suggests a possible link between the two.
--It is natural for people to go to bed when they are sick. Substances produced by the immune system to help fight infection also cause fatigue. One theory proposes that the immune system evolved "sleepiness inducing factors" because inactivity and sleep provided an advantage: those who slept more when faced with an infection were better able to fight that infection than those who slept less. In fact, research in animals suggests that those animals who obtain more deep sleep following experimental challenge by microbial infection have a better chance of survival.
If you're considering an eye mask to maximize your nap and/or nighttime sleep, here's the good news: it won't break the bank. The eye mask pictured above runs $2.95, and you can find one on Amazon for $2.56. I can't vouch for how "good" these masks are, but based upon the fact that I use a mask that I received free from an airline on an overnight flight, I think just about any one will do.
Personal note: If you choose to use an eye mask in the middle of the day, I do recommend allowing your eyes to become slowly accustomed to the light at the conclusion of your nap. You won't believe how sensitive your eyes are after you've been wearing a mask! Particularly on a sunny afternoon, don't immediately take off the mask and open your eyes. Instead, remove the mask, but keep your eyes shut for another minute or two while they adjust to the light filtering through your eyelids. I know it sounds like a simple thing - but believe me, when you open your eyes too quickly after using the mask, it doesn't feel so great!
Interestingly, I just attended the LFA DMV Virginia Summit this past weekend in Richmond, and I caught the tail end of a great talk about Memory and Lupus Fog, given by Dr. Aarat Patel. He mentioned two books about sleep - one, simply called, "Sleep", and another called "Lights Out!". I think both books talk a lot about this concept of light and how it affects our sleep. Happy reading, and happy napping!