You come home after a long day of work and want to relax by checking Facebook posts, reading a book online or surfing the Internet. But, even though it’s way past your bedtime when you finally put the ipad down and close your eyes, you find you can’t doze off. It’s pretty frustrating. What is going on?
What is Blue Light?
The devices we use, such as fluorescent and LED lighting, computer monitors and smartphones, use blue light. The problem with the blue light is that it can break down melatonin, which is a chemical produced by the pineal gland and helps us to sleep by regulating the sleep cycle. The blue light is making us feel more awake, according to the National Institutes of Health. (https://www.ncbi.nlm.nih.gov/pubmed/21552190)
Just think about how regularly you use your laptop to read emails or watch movies before bed—that adds up to a lot of disrupted sleep.
Research on Blue Light
In a Harvard research experiment, people were exposed to 6.5 hours of blue light. They were also exposed to green light for the same amount of time. The result was that blue light suppressed melatonin for about two times as long as the green light.
Normally, your brain releases melatonin a few hours prior to bedtime, reaching its highest point in the middle of the night. But, with blue light, the melatonin’s release is delayed—and it takes longer for you to get to sleep.
According to Scientific American, (https://www.scientificamerican.com/article/q-a-why-is-blue-light-before-bedtime-bad-for-sleep/), you also get less REM sleep (a kind of sleep that occurs at intervals during the night and is characterized by rapid eye movements, more dreaming and bodily movement, and faster pulse and breathing). When you wake up, you may feel tired even if you’ve had eight hours of sleep.
Children and Blue Light
You may want to have your children turn off their electronic devices well before bedtime because of the blue light emanating from the screen. This will give them a good night’s rest and be fully awake for school the next day. The following are some things you can do to help your children get sound sleep.
- Give children a time to turn off all electronics—one or two hours is optimal in order to get their bodies to produce more melatonin.
- If children are still at work on school projects and need to stay up to work on their devices, dim the brightness level on the screen.
- Install the app that warms the colors on the screen. Stay away from blues, and focus on the reds and yellows.
- Try not to use the energy-efficient lightbulbs in nightlights. Instead, use dim, red lights, because red doesn’t cause the melatonin to be restrained.
- Andrew Simon, a naturopathic physician at the Bastyr Center for Natural Health, suggested changing all overhead lights to full spectrum if possible. In addition, he advises to use some of the new smart home tech solutions to have lights turn off gradually or at a certain time to help encourage the body’s natural sleep/wake cycle.
Health Effects of Blue Light
Research has shown that people who work the night shift with exposure to blue light had high risks of several diseases. Any kind of light can prevent the secretion of sleep-inducing melatonin, but blue light in the evening is more powerful.
Blue light can contribute to the following health risks.
- The low melatonin levels may play a part in causing breast and prostate cancer.
- The light in the evening causes us to get less sleep, putting us at an increased risk of depression.
- Anterior structures of the human eye, such as the cornea and lens, block the ultraviolet rays from the retina, which is at the back of the eye. But, visible blue light passes through the cornea and lens, reaching the retina. (Sunglasses that block ultraviolet rays are important to protect the eyes from damage that could cause cataracts, snow blindness or cancer.)
Shedding Light on How You Can Protect Yourself
- Use dim, red lights for nightlights, because the red light will suppress melatonin the least.
- For about two to three hours prior to bedtime, don’t look at bright screens.
- If you work at night and use electronic devices, you may want to invest in blue-blocking glasses. Or, you can use an app that filters a blue/green wavelength at night instead.
- Try to get lots of light during the daytime—it may help you to sleep better at night and lift your mood. It will also keep you sharp during the day.
Not all Blue Light is Harmful
It’s important to note that not all blue light is bad for you. Research has shown that it boosts alertness, helps the memory and cognitive functions and elevates the mood. Light therapy is used to treat seasonal affective disorder, a depression that’s related to the changes in seasons. This therapy emits bright, white light that has blue light rays.