How Blue Light Can Affect Your Sleep

blue light and sleep apnea

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.


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).

For whatever reason someone may 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.

The natural body clock

Our biological clock determines our sleeping routines or our circadian rhythm. A 24-hour body clock controls our sleep/wake cycle. 

The circadian rhythm uses light signals to adjust the body clock, most notably the light from day time and night time. In years gone by, this was all the light sources our bodies had. However, with the invention of artificial lighting and, more recently, electronic screens of all descriptions, our body clocks have a lot more sensory input to deal with.

Screens and their impact on sleep patterns

The proliferation 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 be why so many people experience difficulty falling asleep.

natural daylight

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. 

Some studies have even linked exposure to light at night time as an increased risk factor for health conditions like cancer, heart disease, type 2 diabetes and obesity.

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 level of brightness. 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.

What you can do

Wearing tinted glasses could be extremely useful for people who have to work at night or keep irregular hours for whatever reason. 

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. 

Of course, there are other tips to help ease your body into sleep mode. Turning off lights where possible or dimming them is a good starting point. 

You may try switching to red lights for night-time lighting as this colour suppresses melatonin the least. 

Removing the temptation of screens from the bedroom — and avoiding screens for two or three hours before bedtime — can also help promote good sleep.

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.

Outdoor natural light

Also important is trying to expose yourself to plenty of bright outdoor light during the day. This will also benefit your body clock, helping keep you alert during the day and tired at night.

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

Author robertf