"Circadian Rhythm" &
The Circadian Rhythm generally known as our Body Clock, controls our Sleep-Wake Cycle as well as our metabolism, memory, healing ability and cognitive ability. It uses light and darkness as cues to determine whether we should be awake or sleeping. When the sky is dim, our eyes will send signals to the brain telling us it is time for bed.
Melatonin is no longer a myth!
Everyone has a Body Clock in their brain, which has a cycle of about 24 hours. The body clock regulates being awake or asleep through a variety of hormone secretions from the brain, including Melatonin, Serotonin and Dopamine. Light is an essential signal for our body clock to distinguish between day and night, as the body’s secretion of Melatonin varies according to light intensity. When the surrounding environment becomes dark, Melatonin secretion will increase, making us naturally drowsy. On the contrary, if the eyes receive a strong light source, Melatonin in the body will decrease. At night, artificial light sources such as televisions, computers and handheld devices, transmit light to the brain that inhibits Melatonin production. Thus misleading our body clock to believe it is day time, and making it difficult for us to fall asleep.
Circadian Rhythm Disorder
The condition of our health gradually changes over time. If we suffer from chronic diseases, it will affect our sleep quality. Menopause that causes hot flashes, changes in breathing and reductions in hormone secretion that may disrupt sleep. Therefore, older people progressively struggle to obtain a sound sleep. The interchange of awake and asleep throughout the whole night, making it seems like the sleeping time is shortened. This has created a misconception that sleeping reduces with age. Furthermore, the younger generation’s constant use of electronic products that emit a large amount of blue light affects the Circadian Rhythm and disrupts sleep.
To improve Circadian Rhythm Disorder, properly maintaining a constant sleeping habit is crucial. The routine time of sleeping and waking up should be kept the same. It is also a good idea to go outside and take a stroll during the day because aerobic exercise and sunlight can help the body and mind stay “awake”. This ultimately enables you to reset the body clock. At the same time, you should reduce your exposure to blue light at night, and avoid using electronic products with LCD screens 1-2 hours before going to bed, so that your brain can naturally release Melatonin and switch your body to sleep mode, which will definitely help improve the overall quality of sleep .
Does blue light help treat sleep disorders?
The main source of light from an LCD screen is blue light, which is widely used in TVs, mobile phones and tablet computers. Blue light has shorter wavelength and higher energy; some studies have pointed out that the light of this spectrum has the greatest impact on the circadian rhythm, so it has been of particular concern by the public. Excessive absorption of blue light before bedtime leads to the suppression of melatonin secretion, which affects sleep is undisputed. However, recent medical research also pointed out that blue light can help improve the mental state in the daytime and has gradually become an important tool for the treatment of sleep disorders. An interesting British study found that installing blue light in the office can enhance the alertness, work performance, and even the quality of sleep at night. In any case, when using electronic products, we should still exercise proper control. It is recommended to rest the eyes for 5-10 minutes every 30 minutes to avoid discomfort such as dry eyes.
 美國國家睡眠基金會 - https://www.sleepfoundation.org/articles/what-circadian-rhythm
ﾠ香港大學心理學系睡眠研究所 - http://www.psychology.hku.hk/sleep/SleepEducation/ControlOfSleep.html