By: Sophie Gabreldar
Many people stay up late watching TV or using their phones, but this can be detrimental to their health. The blue light coming from these screens can prevent the release of sleep-inducing melatonin. This increases alertness, and resets your body’s internal clock (known as your circadian rhythm) to a later schedule. This causes the body to take longer to fall asleep; and to have less REM sleep (where dreams occur) making the body wake up feeling tired.
How Does Blue Light Affect Sleep?
Blue-wavelength light stimulates the sensors in your eyes to send signals to your brain’s internal clock to keep you awake. Sunlight and white light contain a mixture of different wavelengths, and both have a significant amount of blue light. During the day this is good, blue light helps you stay alert while improving your performance and mood.
The pineal gland in your brain receives information about light-dark cycles from the environment to know when to release melatonin. When it gets dark, the pineal gland in produces melatonin, which tells your body to become tired. Normally, the pineal gland begins to release melatonin a couple of hours before bedtime, and reaches its peak in the middle of the night. Unfortunately, blue light, whether from the sun or a screen, often inhibits melatonin production. This reduces both quantity and quality of your sleep.
Blue light tricks your brain into thinking it’s daytime, leading to a suppression in the release of melatonin, thus disrupting your circadian rhythm. Various studies have shown that a suppression in melatonin is linked to several health problems such as obesity, cancer and depression.
Reducing Blue Light Exposure
Amber-tinted glasses offer the easiest and most effective way to avoid blue light exposure at night. These glasses effectively block almost all blue light.
In one study, 20 individuals used either blue-light-blocking glasses or glasses that didn’t block blue light for 3 hours before bedtime. The former group experienced major improvements in both sleep quality and mood. The glasses had also been found to greatly improve sleep in shift works when worn before bedtime.
If you don’t want to use glasses every night, a few other ways exist to reduce blue light exposure. Some other ways to block blue light include dimming or turning off the lights in your home and installing an app that adjusts the light your laptop or smartphone emits.