Blue Light and Sleep (What You Need to Know)

We’ve all been there. Scrolling through social media feeds or watching an episode of our favorite show on Netflix just before we go to bed.

But did you know that using digital screens late in the evening may be affecting the quality of your sleep?

Blue light and sleep

Research shows that rather than making us feel relaxed and restful at bedtime, using bright white screens before bed can actually increase our alertness and disrupt your body’s internal clock.

Blue light is part of the visible light spectrum with the highest energy. Many digital screens emit high-intensity blue light which sends signals to your body that it should be awake.

The light doesn’t necessarily appear ‘blue’. It’s actually part of the spectrum of any bright light.

In fact, sunlight provides a natural source of blue light which is helpful for us. When it’s daytime, it tells our body that we need to be awake and alert. When the sun has set, it tells our body that it’s time to start preparing for sleep.

Yet, in today’s world there are more and more artificial sources of blue light. The screens from smartphones, laptops and tablets can make our body think it should be awake, even when it’s really time to rest.

Blue light and melatonin

We all have an approximately 24-hour internal clock known as a circadian rhythm. This is what helps our bodies determine when we feel sleepy and when we feel awake.

Naturally, light and darkness regulate this rhythm by triggering the release of melatonin, the sleep-inducing hormone.

The blue light emitted from digital device screens can delay the release of the melatonin.

The National Sleep Foundation says:

“The reason that blue light is so problematic is that it has a short wavelength that affects levels of melatonin more than any other wavelength does. Light from fluorescent bulbs and LED lights can produce the same effect. Normally, the pineal gland in the brain begins to release melatonin a couple of hours before bedtime, and melatonin reaches its peak in the middle of the night. When people read on a blue light-emitting device (like a tablet, rather than from a printed book) in the evening, it takes them longer to fall asleep; plus, they tend to have less REM sleep (when dreams occur) and wake up feeling sleepier— even after eight hours of shuteye.”

Blue light and sleep study

Many studies now show that blue light affects our circadian rhythm. The University of Toronto conducted a study where the participants were instructed to wear special glasses that blocked blue light wavelengths. The people in the study that wore these glasses produced more melatonin than those who didn’t.

Furthermore, other medical studies demonstrate that blue light wavelengths are responsible for suppressing delta brain waves, which can help you sleep. In contrast, blue light produces alpha wavelengths, which make you more alert.

The blue light from phone screens can affect our circadian rhythm and make it more difficult to get to sleep.

Other research has found a link between blue light and more serious health risks such as insomnia, and even diabetes.

How to get a better night’s sleep (and reduce blue light)

Blue light can have a big impact on the quality of your sleep. Here’s a few ways you can fix it:

Don’t use devices before bed: Try turning off all devices at least 1 hour before bed so you are not exposed to a high quantity of blue light directly before you go to sleep. Of course, the earlier that you can switch off devices, the better so try and find whatever seems realistic.

Use blue light blocking glasses: LUMES lenses filter the blue light from your screen and which can help you be exposed to lower levels of blue light during the day. They also come equipped with anti-glare technology that can significantly reduce eye strain. Since LUMES lenses only remove the most harmful parts of the color spectrum, they are virtually clear. Unlike when using dark mode or other blue light-reducing apps such as f.lux, your color perception of the screen will not be noticeably affected. See our range here.

Use different lights before bedtime: LED light bulbs in your house also emit blue light. Instead of using bright white lights, try switching to dimmer red lights closer to bedtime so you are exposed to less blue light.