Sunlight is our natural source of light. With the passage of time, there have been numerous sources of artificial light available to us. But these artificial sources come with their downsides. They contain blue light which has the potential to disrupt our sleep cycles.
It is a well-known fact that blue light has a profound effect on your internal body clock. Sunlight has a considerable amount of blue light. The potent blue light coming from the sun gives you stamina in the mornings. But the sun sets in the evening, and you switch on your artificial lights.The use of artificial lights in the evening makes it difficult for you to fall asleep.
How Does Blue Light Disrupt Sleep?
Your body has an internal clock. This clock controls your circadian rhythm. Your body carries out its internal functions according to the circadian rhythm. The circadian rhythm regulates your sleep, hunger, brain activity, hormone secretion and cell renewal process. Out of all these, the most important biological function of your body is preparing for sleep and being awake.
Your circadian rhythm works according to signals received from the external environment. Your circadian rhythm adjusts itself according to daylight or darkness. The circadian rhythm is connected to the hypothalamus area of your brain.The hypothalamus area of the brain is sensitive to light received from the external environment. Your retina detects light in the external environment and alerts the hypothalamus. The hypothalamus gestures the body to start producing hormones and lower its temperature to prepare for sleep. It is here that the powerful blue light comes into play.
Your eyes don’t have the mechanism to successfully obstruct blue light. The result is that the blue light travels to the back of the retina. This confuses the hypothalamus. It starts believing that it is daytime and it signals our body to stay awake. This short wave blue light also makes us more alert. The shorter wavelength of blue light changes circadian rhythms with double the force as compared to other light colors with longer wavelengths.
Every color light has an impact on our natural sleep and wake cycle. Compared to other colors blue color has a greater ability to disrupt our sleep and wake cycle. The shorter wavelength in blue light makes the body more sensitive to this light.
When it turns dark your body starts producing a hormone called melatonin. This hormone makes you tired and prepares your body for sleep. Blue light hinders the production of this hormone. In comparison to other light colors, blue light has double the capacity to hinder the production of melatonin. This in turn severely diminishes the quality and quantity of our sleep. Blue light affects our REM sleep.
Blue light also stops the body temperature from reducing during the night. Subtle reduction in body temperature is the body’s method of preparing itself for the sleep process. The blue light interferes with this process by maintaining the body temperature at day time levels.
Negative Effects of Blue Light on Your Health
Lack of proper sleep at night can make us tired and sleepy the next day. You wake up feeling more tired and it puts you in a bad mood. Interference with the body’s circadian rhythms can also have long term effects on your health. It can create cardiovascular, metabolic and immune system problems. Disturbed sleep negatively impacts your cognitive function in the long term.
The Various Sources of Blue Light
Sunlight is a natural source of blue light. Smartphones, television, computers are all sources of blue light. Your energy-efficient fluorescent bulbs and LEDs also emit considerable amount of blue light. Handheld video games and LED digital clocks are other sources of blue light. The light emitted by devices is not blue. It appears white to the naked eye. The white light emits wavelengths between 400 to 490 nanometers. This is the wavelength of blue color.
Solving The Problems Caused Due to Exposure to Blue Light.
Blocking all artificial light and using only natural light is the best method for your health. This solution is not viable in modern times. Some other methods to resolve problems caused by blue light are given below:
- Steer clear of artificial light a couple of hours before bedtime. This means staying away from computer, smartphones, television a couple of hours before bedtime.
- Use dim red lights at night. Compared to other light colors, red light has the least power to disrupt circadian rhythms. A dimly lit environment assists the body in producing melatonin.
- Change the lighting in your home in a way that it resembles fire lights. These lights are rich in red and yellow wavelengths. One method to do this is to switch off your overhead LED lights in the evening. Then use floor and table lamps with orange and yellow bulbs.
- If doing work at night is necessary for you then you can invest in glasses which block out blue light. These glasses are expensive but worth their price for solving sleep problems caused due to blue light.
- You can download software which adjusts the light on your computer screen and smartphones depending on the time of the day. There are numerous apps which when installed in computers and smartphones help in reducing blue light during sunset.
- Expose your self to sunlight during daytime. This will improve your mood and your sleep.
- Use the night mode in your apps and computer settings. Smartphones and tablets have night shift mode which change the blue wavelengths to warm red wavelengths.
Exposure to artificial light is inevitable in our modern-day lives. The timing of exposure to blue light is important in determining its effects on your health. Exposure to blue light during day time has beneficial outcomes. Some of these are improving alertness, decreasing day time sleepiness and improving your attention span.
It is exposure to blue light after sunset that is harmful to your sleep. You will have to take active steps to reduce your exposure to blue light after sunset so that it does not affect your health negatively.