How does blue light affect sleep?

This is an automatically translated article.

Sleep is one of the key factors contributing to optimal health. However, modern people today tend to sleep less than in previous eras and the quality of sleep also decreases. Poor sleep has been linked to heart disease, type 2 diabetes, depression and obesity. The use of artificial light and electronic devices at night can contribute to these sleep problems.

1. Blue light and biological clock

The human body functions as a clock, regulating the body's circadian rhythm. A circadian cycle is 24 hours long, affecting the functioning of many functions in the body. Most importantly, the circadian clock often determines when the body needs to sleep to rest and when it is time to wake up and get active.
However, the circadian rhythm is formed in large part by signals from the external environment, most importantly light during the day and darkness at night.
Blue wavelength light stimulates sensors in the eyes, which in turn send signals to the body's biological clock. Sunlight and white light contain a mixture of different wavelengths, each with a significant amount of blue light. Receiving blue light, especially from the sun, during the day keeps the body awake and improves performance and mood, so blue light therapy devices can help treat depression. cold .

Ánh sáng xanh — Nên hạn chế sử dụng ánh sáng xanh từ các thiết bị điện tử

At the same time, green light bulbs have been shown to reduce fatigue and improve the mood, work performance and sleep of office workers.
However, many modern light bulbs and electronic devices, especially computer screens, also produce large amounts of blue light and can affect the body's biological clock. When it's dark, the body releases the hormone melatonin, creating a feeling of fatigue and sleepiness.
Blue light, from the sun or a laptop computer has a great effect on suppressing melatonin production, thereby reducing both the number of hours of sleep and the quality of sleep. Studies have linked melatonin suppression in the evening to various health problems, including metabolic syndrome, obesity, cancer, and depression.

2. Use stained glass

Using some kind of red-yellow eyeglasses like amber is the simplest and most effective way to avoid direct exposure to blue light at night. These glasses effectively block blue light from reaching the cornea.
Therefore, the brain will not receive signals from light, helping the biological clock to work properly. Studies show that when users wear blue light-blocking glasses, even in bright rooms or while using electronic devices, the body produces as much melatonin as it does when it's dark.
In one study, the melatonin levels in the human body at night were compared under different conditions, including low light, bright light, and bright light with stained glass. Bright light almost completely inhibits melatonin production, while dim light does not.
Notably, people who wore tinted glasses, their bodies produced the same amount of melatonin as those exposed to dim light. Likewise, blue-light blocking glasses have been shown to make major improvements in sleep quality and psychological well-being.

Kính mắt màu đỏ vàng giúp ngăn chặn tác hại của ánh sáng xanh vào ban đêm

In a 2-week study, 20 individuals used blue light blocking or non-blue light blocking glasses for 3 hours before bedtime. The group that used the glasses reported major improvements in both sleep quality and mood.
Furthermore, in a study in older adults with cataracts, blue light-blocking lenses improved sleep and significantly reduced daytime dysfunction.

3. How to limit blue light

Having to wear a pair of glasses every night before bedtime can be inconvenient for some people, so there are a few other ways to reduce your retina's exposure to blue light.
One common way is to install a program called f.lux on the computer. This program automatically adjusts the appropriate color and brightness of the screen based on the time zone. Similar applications are also available on smartphones.
A few other ways include:
Turn off all lights in the house 1 to 2 hours before bed Use a red or orange reading light that doesn't emit blue light Keep your bedroom completely dark or Use a sleeping mask

Đèn học — Nên dùng đèn học có màu cam để bảo vệ mắt

Exposure to blue light during the day, especially sunlight is also important for maintaining a good night's sleep. If outdoor activities are not available, customers should consider using a blue light therapy device - a powerful lamp that simulates the sun to ensure the operation of the body's biological clock.
For direct consultation, please dial HOTLINE or register online HERE.
Reference article: Healthline.com