August 23, 2017 - Eye Health
Sleep is one of the keystone pillars of good health, right alongside a good diet and exercise. Studies have shown that a lack of sleep increases the likelihood of a host of chronic conditions including depression and diabetes.
How blue light affects your body clock
Melatonin, which is produced in the pineal gland, is the hormone responsible for sleep regulation. Your body clock is responsible for telling the pineal gland when to increase or decrease its production of melatonin. When you should be sleeping, melatonin production increases, and vice versa.
Melatonin production has been proven to be affected by external factors. Research has found that light, specifically blue light, is one of the strongest environmental factors that influence melatonin production. However, our bodies have not yet evolved to differentiate light from electronic devices or natural sources. While it makes sense for our body to suppress melatonin production during the day (sunlight), it does not make sense to suppress melatonin production during the last Netflix episode before bed. If you are exposed to blue light close to your resting hours, you may find it difficult to fall asleep and experience a reduced quality of sleep.
Researchers have found that another type of photoreceptor is responsible for regulating melatonin production in the retina. These wavelength-sensitive photoreceptors are known as melanopsin-containing ganglion cells. These are the retinal cells stimulated when looking at blue light.
Short-wavelength [blue] light has a greater effect on phase shifting the circadian clock and on melatonin suppression. Numerous studies have shown that people who read on blue light-emitting devices took longer to fall asleep, reduced REM, and had heightened vigilance before going to sleep. In other words, when you are exposed to blue light, your melatonin production will be suppressed and you may find it difficult to get a restful nights sleep.
What can you do?
Today, this understanding of blue light is widely recognized in the medical community. Major manufacturers of electronic devices have caught wind as well, and are implementing ‘night modes’ for many of their devices.
To improve sleep, it is recommended to avoid using electronic devices after 6pm. If you do find yourself using your advice after 6pm, you can still improve sleep by reducing the brightness on your device, using blue-blocking glasses or blue-blocking screen, and reversing your device to have light text on a dark page.
