What Keeps Us Counting Sheep


While we all know the benefits of sleep and the dangers of not getting enough, lifestyle quirks such as lighting could be stopping us from getting our rest.

Hotel roomOur demanding and fast-paced world of classes, jobs, and internet memes keep us from our mattresses until the wee hours of the morning. Yet, even after our devices shut down and finished assignments lay in our folders, 41.9% of young adults lay awake at night, missing out on necessary downtime. These insomniacs are at a disadvantage in terms of memory and function, as well as in health: heart disease, obesity, depression, and attention problems are associated with sleeplessness. Aside from the obvious advice that we should sleep earlier, deeper, and more, what can be done to avoid the health effects of sleeplessness and guarantee fewer nights spent counting sheep?

Thanks to how our bodies regulate sleep, our ability to doze off at night can be affected by what we do hours before bedtime. Circadian rhythms, which are daily cycles that dictate sleepiness and activity, are associated with marked fluctuations in levels of melatonin, an important regulatory hormone. Secreted by the pineal gland, melatonin levels in the blood plasma increase prior to bedtime and stop early in the morning. In one study published by the the Journal of Clinical Endocrinology & Metabolism, researchers assembled a group of 104 young adults and conducted studies to see the effects of light levels on melatonin secretion. While it’s clear that sleeping in darkness is far easier than sleeping in floodlights, the intensity of light hours before we think of bedtime can affect melatonin onset and duration, thus affecting the quality and length of snoozes.

Anyone who has focused on a computer screen or peered into the sun knows that not all light is equally intense. Light’s intensity is measured in “Lux” (lumens per square meter), an SI flux unit that quantifies how bright a light is by measuring how much visible light strikes an area. While the summer sunshine can be as much as 50,000 Lux, and a typical office 300-500 Lux, a night sky can be as dim as 0.1-1 Lux. In the study, subjects were exposed to either 200 Lux light or < 3 Lux for 8 hours before sleep. In the adults exposed to the higher light level, the start of melatonin synthesis happened 23 mins before the scheduled bedtime, while in dim light, synthesis occurred nearly 2 hours before the scheduled bedtime– as a result, melatonin duration was shortened in the higher light subjects. The synthesis and secretion of melatonin is a prelude to bedtime and contributes to sleepiness, suggesting that delaying its onset and shortening its duration may result in insomnia.

How To Light Yourself to Bed
1. Tone it Down
Limit exposure to intense light before bed, scheduling computer use and work earlier in the evening and leaving dimmer activities such as reading for later. Though a radical rescheduling of activities around light exposure may be impractical, cutting short time spent on Angry Birds and Reddit at night will be better for your health and sleep.

2. Change your colors
In addition to intensity, a characteristic of light called “color balance” can also have an effect on melatonin levels (and therefore sleepiness). Color balance, measured in degrees Kelvin, quantifies the warm redness or cool blueness of different kinds of light. Imagine a glowing candle in a dark room and compare it to a harsh fluorescent light in an office. While some consumers complain about the sharpness and coldness of home fluorescent lighting, color balance has a quantifiable effect on salivary melatonin levels and sleep quality. Incandescent lights, which are significantly skewed towards the orange side of the light spectrum, disrupt melatonin secretion less than their eco-friendly cousins. To compromise between environmental responsibility and comfort, you can pick up “softened” fluorescent lighting at hardware stores with color balances near 3000K. While they run as efficiently as fluorescent bulbs, these special softened bulbs have filtering coatings to block certain wavelengths and produce more agreeable lighting.

3. Darken your Devices
Can’t get away from the computer but still need a good night’s sleep? Toning down brightness settings effectively lowers the number of lumens emitted from the screen, thus reducing the amount of light. Another tactic that can help you realize your dreams is the use of applications made for adjusting lighting based on the time of day, such as f.lux, which changes the color balance and brightness of monitors to adapt to environmental changes.

While we all know the benefits of sleep and the dangers of not getting enough, lifestyle quirks such as lighting could be stopping us from getting our rest.

Alexandra Ding is a Brevia staff writer. She can be reached at alexandrading01@college.harvard.edu.