How Blue Light Can Affect Your Sleep

Last updated on July 7th, 2023 at 11:25 am

Sleep plays an essential role in maintaining our overall health and well-being. While we are asleep, our bodies undergo several processes that help them recover from the day just gone and prepare for the one ahead. Let’s take a look at how blue light can affect your sleep.

Lack of sleep and the health implications

Lack of sleep has been linked to various health conditions, including heart disease, type 2 diabetes, obesity, lower immunity levels and depression. Yet people can struggle to get the quality rest they need due to stress, anxiety, poor diet and sleeping disorders — including obstructive sleep apnoea (OSA).

If you struggle to get a good night’s sleep, doctors recommend changing bad habits such as eating heavy meals or consuming alcohol before going to bed. Another suggestion will be to eliminate any electronic screen time before sleeping.

What is OSA?

Obstructive Sleep Apnoea is when your airways close during sleep, causing you to stop breathing. The breathing pauses can occur up to 400 times per night, followed by symptoms such as choking during sleep and snoring.

The natural body clock

Our biological clock determines our sleeping routines or our circadian rhythm. 

What is circadian rhythm?

Circadian rhythms are 24-hour cycles that control our sleep/wake cycle. 

The human body follows circadian rhythms, all connecting to a master clock in the brain. Circadian rhythms use light signals to adjust the body clock, most notably the light from daytime and nighttime. These rhythms let our bodies know when to be awake and when to sleep.

In years gone by, daylight and night were all the light sources our bodies had.

However, with the invention of artificial lighting and electronic screens of all descriptions, our body clocks have a lot more sensory input to handle.

What happens when your circadian rhythm is off?

When your circadian rhythm is off, your body does not function properly. When your body’s internal clock does not give off the correct signals, you can struggle to fall asleep and regularly wake up at night. When your sleep is broken and your circadian rhythm is disrupted, your sleep quality is reduced. 

A disrupted circadian rhythm has been linked to sleep disorders, such as Obstructive Sleep Apnoea. 

Screens and their impact on sleep patterns

The growth of electronic screens in our everyday lives has increased our exposure to blue light.

Modern-day energy-efficient lighting also emits more light on this colour wavelength. We are exposed to blue-coloured light during the day, mainly from sunlight when we are out and about. However, this is good as it helps increase our levels of alertness while also improving our mood and performance. 

It is the increase in exposure to blue light at night which can cause so many people to experience difficulty falling asleep. Blue light before sleep prevents natural melatonin, which disrupts your sleep cycle.

Daylight and melatonin

As the day’s light starts to fall, the hormone melatonin is released, which tells the body to get tired and prepare for sleep. This is where exposure to light sources at night can be an issue, as it can suppress melatonin production and lead to sleeping problems. 

Night light and melatonin

Any light at night will see a drop in melatonin production, but blue light has the most significant impact and the reason this aspect of modern-day life can be detrimental to a good sleeping routine. 

In one study at Harvard, the effects of blue and green light were analysed. The researchers compared the impact of 6.5 hours of exposure to both colours at a comparable brightness level. The outcome was the light on the blue wavelength suppressed the production of melatonin for around twice as long compared to exposure to green light. 

The University of Toronto studied melatonin production by making participants wear goggles, which blocked blue-coloured light. The result showed that those in the test group who wore the goggles had the same melatonin levels as those without goggles exposed to normal dim light levels.

Research conclusions

Given the Harvard study results and the University of Toronto’s findings. Blue-coloured light impacts the production of melatonin in the body, and the implication this has on the body clock affects our sleep. It also points to one of the ways to offset the problem of blue night light.

How to reduce blue light exposure at night

We do not have full control of our circadian rhythm, but there are things you can do to help maintain quality sleep.

• Wearing tinted glasses could be extremely useful for people who have to work at night or keep irregular hours. Amber-tinted glasses are one of the most effective ways to counter the blue light emitted by electronic devices. Blocking the blue light will allow your natural melatonin to regulate your sleep. 
• Instal the f.lux application this works by automatically adjusting the colour and brightness of your screen based on your timezone; when it is dark, the app blocks blue light. There are also smartphone apps that do the same thing (Twilight, Iris or LightBulb).
• Switch to night mode on your smart device to block blue light.
• Turning off lights where possible or dimming them. 
• Removing the temptation of screens from the bedroom and avoiding screens for two or three hours before bedtime can also help promote good sleep.
• Daylight exposure – Daily exposure to sunlight and exercise will help your body clock. Exposure to daylight keeps you alert throughout the day and tired at night. Daily exercise can also help to reduce OSA symptoms.

Try taking a melatonin supplement to help regulate your sleep-wake cycle. Taking a melatonin supplement can help reset your inner “sleep clock” so you fall asleep more easily.

Make Changes to Improve Your Health

Consistently disrupted sleep can have detrimental effects on your health. For those with disorders such as obstructive sleep apnoea, the nature of any treatment plan can be affected by difficulties falling asleep. 

Therefore, addressing the level of blue light you are exposed to at night time is essential in setting your body clock and ensuring a good sleep routine.

If you think you have OSA and have not yet been diagnosed, take an In-Home Sleep Test. 

If you need any help regarding your OSA, please contact us.