The Correlation Between Light and Decreased Quality of Sleep

Dr. Craig Hudson, MD | November 28, 2016


In previous blog posts, we have touched on how sleeping in a fully darkened room can be beneficial to the overall quality of sleep you receive. In this blog post, we will discuss how and why light exposure impacts your quality AND quantity of sleep.

Light Exposure Plays on Your Nerves

In today’s culture, exposure to unnatural light well past sundown is the norm. Many of us are exposed to large amounts of unnatural light just before bed. Whether it is because we are working late, relaxing in front of the TV or eating a late dinner, light has a significant role to play in our afterhour activities. All of this extended exposure to light can impact our body chemistry in ways that can be damaging to our health.

When our eyes take in light, the exposure leads to the stimulation of our retinas and certain nerve pathways that lead from the eye to the section of the brain that has control of body temperature regulation and hormones. The retinas are the brain’s connection to the outside world with regards to tracking time. They communicate the time of day (daytime or nighttime) based on how much light they detect. The brain then accepts this information and sets the internal body clock, which includes sleep patterns. By extending our exposure to light to later and later hours, we are effectively delaying the sleep phase of our body clock.

Disrupting Hormones With Late Night Light

The production of melatonin, one of the hormones chiefly responsible for triggering drowsiness, is controlled by light exposure. The brain will halt the production of melatonin as long as light is detected. According to researchers, room light exposure during regular sleeping hours can reduce the melatonin levels in the body by more than 50%. Even having the light on just before bed can cut into the amount of time your body spends producing melatonin by about 90 minutes.

A chronically low production of this hormone can negatively impact your body’s temperature self-regulation process, your blood pressure, the overall quality or “restfulness” of your sleep and your glucose levels. Overtime, these symptoms could turn into health issues (i.e. diabetes, insomnia, high blood pressure and depression).

You might think that reducing your light exposure during your sleeping hours is not feasible, especially if you are a shift worker, but simple tricks like wearing a sleeping mask can be extremely helpful.

Get your own sleeping mask in our Zenbev Starter Special! You will also receive a jar of our all-natural drink mix to help you get to sleep faster, and a copy of "Feel Great Day & Night" by Dr. Craig Hudson for even more helpful hints on getting a restful sleep!