What are circadian rhythms?
To understand how blue light affects sleeping patterns the first thing to mention is the Circadian rhythm. Circadian rhythms are 24-hour cycles that are part of the body’s internal clock. One of the most important and well-known circadian rhythms is the sleep-wake cycle. When working correctly, a circadian rhythm allows for consistent and restorative sleep. But when thrown off, it can cause sleeping problems.
They are directly influenced by environmental cues, especially light, which is why circadian rhythms are tied to the cycle of day and night.
During the day, light exposure prompts alertness and keeps us awake and active. While at night, a lack of light signals to our bodies to produce melatonin, a hormone that prompts sleepiness. And so we have a sleep-wake cycle.
What happens when our sleep-wake cycle goes wrong?
Our bodies don’t work efficiently and we can struggle to fall asleep, we wake during the night or wake very early in the morning. Overall we get a lower quality of sleep and feel tired during the day.
What can we do to protect a healthy sleep pattern?
- Expose ourselves to natural light early in the day; take a walk outside.
- Get exercise.
- Follow a consistent sleep routine.
- Limit our exposure to blue light later in the day.
Number four above ‘limit exposure to blue light’ is very important in the world we live in today. Light exposure is everywhere and the short wavelength light known as blue light is becoming more and more plentiful. It is emitted from our digital devices, tv screens and even energy-efficient light sources.
So how do I limit exposure to blue light at night?
You can limit the amount of blue light entering your eyes in a number of ways. One of the easiest ways to do this is by wearing blue light blocking glasses. These blue light blocking glasses filter out a large amount of the blue light emitted from screens before it hits your eye. By wearing these blue light filtering glasses later in the day you can limit some of the disruption caused by screens to your melatonin levels. This can reduce the effect the blue light has on the all important sleep-wake cycle.
Limiting screen time in the 2-3 hours before bedtime is hugely important to reduce the amount of blue light you are exposed to. Social media and other interactive forms of media are especially disruptive to sleep. Limiting this screen time is easier said than done, so if it can’t be avoided, e.g. for work, blue light glasses can be beneficial here.
As there has been a large increase in the number of people working and studying from home as well as binge watching tv, there has been a significant increase in screen time for many people. This is causing a greater exposure to blue light and its effects. New research seen in the Journal of Applied Psychology has shown that wearing blue light blocking glasses before bed can lead to better sleep and even better decision making and a better productivity at work.
Blue light blocking glasses may also be of benefit to those who work night shifts as they are exposed to artificial light and may find it difficult to sleep when they get home.