How does light affect sleep?

Light can affect sleep, we must first start with melatonin. The pineal gland of the human brain secretes a hormone called melatonin, and this hormone will guide us to fall asleep and improve the quality of sleep. Therefore, melatonin is an important factor affecting our sleep.

The secretion of melatonin has a circadian rhythm. After night falls, the light stimulation weakens, and the enzyme activity of the pineal gland to synthesize melatonin increases. The secretion level of melatonin in the body also increases accordingly, reaching a peak at 3 a.m. The level of melatonin at night directly affects the quality of sleep.

With age, the pineal gland shrinks until it becomes calcified, causing the rhythm of the biological clock to weaken or disappear, especially after the age of 35, the body's melatonin secretion decreases significantly.

How does light affect melatonin secretion?

There is a very small cell in our retina called non-imaging visual cells (ipRGC). As the name suggests, this type of cell does not help us see things but can perceive light. When this type of cell feels light, It will send a signal to our circadian pacemaker-the suprachiasmatic nucleus (SCN), and then the suprachiasmatic nucleus informs the pineal gland to secrete corresponding hormones, which play a role in regulating our biological clock. When the light is strong, the secretion of melatonin will be less, and when the light is weakened, the secretion of melatonin will increase.

Can the light of a specific wavelength improve sleep?

In 2000, Harvard Medical School, Brigham and Women's Hospital, and other institutions conducted a nine-day experiment on 23 volunteers and concluded that light has a significant effect on the secretion of melatonin in the human body.

A research report in the "Chinese Journal of Sports Medicine" in July 2010 showed that 30 minutes of red light per day can help promote female basketball players improve their sleep quality after training.

In 2004, Australian professors Helen and Leon’s research showed that the shorter wavelengths of 470, 495, and 525nm led to the earliest secretion of melatonin, about 40-60 minutes earlier. This more accurately shows that the effects of light of different wavelengths on the secretion of melatonin in the human body have obvious differences.

Studies have shown that blue-green light with wavelengths of 470, 495, and 525nm can inhibit the secretion of melatonin during the day and make the secretion of melatonin more advanced when the night comes. The above cases show that red light can promote the secretion of melatonin, while blue-green light can delay the secretion of melatonin until night.

To have a normal biological clock and healthy sleep, we still have to be exposed to outdoor sunlight during the day, especially during the morning when we get up, so that the light can reduce the secretion of melatonin, and we need to avoid blue and green light at night. Everyone's daily secretion of melatonin is constant, and the secretion is small during the day. If the light is dark at night, the melatonin will be secreted at night.

If conditions do not permit, you can also use bio clock glasses designed based on the above optical principles for auxiliary adjustment. The glasses have two modes of red light and green light. Red light irradiates the retina to promote the secretion of melatonin and make the human body quickly enter sleep. Status: Illuminating the retina with green light can inhibit the secretion of melatonin and make the brain wake up quickly, thereby regulating the rhythm of the body's biological clock. This is the healthiest and most effective way.

Improve the sleep environment

We recommend that the sleeping room environment be stable and consistent. In this way, the body can connect the surrounding environment and sleep, so that you can sleep better.

We know from life and rest: the body's circadian clock produces a circadian rhythm, but environmental factors such as sunlight will also affect the circadian rhythm. So the light in the sleep environment needs to be dark. At this time, a floor light with adjustable light brightness is very important. Usually can choose bright light to meet the daily needs of reading and other work. You can choose sleep mode before going to bed, warm light, and gentle light to create an atmosphere of sleep. It is better to add an automatic shutdown mode to let you sleep safely. The Sunmory floor lamp can satisfy you. Sunmory arc floor lamp has two modes: footswitch and remote control switch, which is easy to use and easy for children to use. The black arc floor lamp has a 1-hour timer function and can be used before going to bed to help you fall asleep better.