Light is an electromagnetic wave.
These waves vary in length, forming a wavelength spectrum. Visible light – the light our eyes can see – occupies a minimal spectrum range, from about 400 to 700 nanometers.
Starting at the longer end (700nm) of the visible spectrum is red, then as the wavelengths get shorter, the colors progress through the rainbow, reaching blues and purples around 400nm.
The invisible light with longer wavelengths than red is called infrared (and becomes radar and radio waves at even longer wavelengths). The invisible light with shorter wavelengths than blue and purple is called ultraviolet (x-rays and gamma rays have even shorter, more energized waves).
Most of the light that surrounds us contains all of the visible spectrum colors, and often some invisible light too. Sunlight, for example, includes the full range of visible light, plus some ultraviolet which causes sunburns and skin damage due to its heightened energy.
Light and Your Sleep-Wake Cycle
Your body’s natural sleep-wake cycle is regulated by the amount of light and darkness we’re exposed to.
In the most simple terms, when our eyes are exposed to light, it signals to the brain that it’s time to be awake and alert. Darkness tells our brains that it’s time to wind down and prepare for sleep.
This process involves a hormone called melatonin. Light exposure suppresses melatonin production, while darkness promotes it.
With the proliferation of artificial light and electronic devices over the past 100 years, our exposure to light has shifted dramatically from mostly natural daylight and darkness to near-constant exposure to artificial light.
With its relatively short wavelength and higher energy, blue light appears to be especially effective at suppressing melatonin. This can increase alertness and wakefulness – which is great during the day but can prevent us from resting when trying to sleep at night.
Blue Light, Disrupted Sleep, and Negative Health Outcomes
Blue light does not contribute to macular degeneration and is unlikely to cause eye problems directly.
However, its tendency to disrupt our sleep may lead to several health consequences.
Disordered sleep and decreased melatonin levels have been linked to the development of chronic diseases and conditions such as:
- cancer
- cardiovascular diseases
- reproduction issues
- endometriosis
- gastrointestinal and digestive problems
- diabetes
- obesity
- depression
- bipolar spectrum disorders
- cognitive impairment
That doesn’t mean that blue light is the leading cause of these health problems, but it’s something to be aware of as a possible contributing factor.
Tips For Reducing Unhelpful Blue Light Exposure
There are several things you can do to reduce your exposure to blue light and the negative effects it may have on your sleep. Here are some tips:
Reduce screen time (computers, TV, cell phones, tablets) in the hours leading up to sleep.
If you can’t avoid screens entirely, try using a software program or app that filters out blue light.
Install warm-colored LED light bulbs in your lamps to use at night. This can give you enough light to see without disrupting your ability to fall asleep – and it makes sweet mood lighting.
Light is an electromagnetic wave.
These waves vary in length, forming a wavelength spectrum. Visible light – the light our eyes can see – occupies a minimal spectrum range, from about 400 to 700 nanometers.
Starting at the longer end (700nm) of the visible spectrum is red, then as the wavelengths get shorter, the colors progress through the rainbow, reaching blues and purples around 400nm.
The invisible light with longer wavelengths than red is called infrared (and becomes radar and radio waves at even longer wavelengths). The invisible light with shorter wavelengths than blue and purple is called ultraviolet (x-rays and gamma rays have even shorter, more energized waves).
Most of the light that surrounds us contains all of the visible spectrum colors, and often some invisible light too. Sunlight, for example, includes the full range of visible light, plus some ultraviolet which causes sunburns and skin damage due to its heightened energy.
Light and Your Sleep-Wake Cycle
Your body’s natural sleep-wake cycle is regulated by the amount of light and darkness we’re exposed to.
In the most simple terms, when our eyes are exposed to light, it signals to the brain that it’s time to be awake and alert. Darkness tells our brains that it’s time to wind down and prepare for sleep.
This process involves a hormone called melatonin. Light exposure suppresses melatonin production, while darkness promotes it.
With the proliferation of artificial light and electronic devices over the past 100 years, our exposure to light has shifted dramatically from mostly natural daylight and darkness to near-constant exposure to artificial light.
With its relatively short wavelength and higher energy, blue light appears to be especially effective at suppressing melatonin. This can increase alertness and wakefulness – which is great during the day but can prevent us from resting when trying to sleep at night.
Blue Light, Disrupted Sleep, and Negative Health Outcomes
Blue light does not contribute to macular degeneration and is unlikely to cause eye problems directly.
However, its tendency to disrupt our sleep may lead to several health consequences.
Disordered sleep and decreased melatonin levels have been linked to the development of chronic diseases and conditions such as:
- cancer
- cardiovascular diseases
- reproduction issues
- endometriosis
- gastrointestinal and digestive problems
- diabetes
- obesity
- depression
- bipolar spectrum disorders
- cognitive impairment
That doesn’t mean that blue light is the leading cause of these health problems, but it’s something to be aware of as a possible contributing factor.
Tips For Reducing Unhelpful Blue Light Exposure
There are several things you can do to reduce your exposure to blue light and the negative effects it may have on your sleep. Here are some tips:
Reduce screen time (computers, TV, cell phones, tablets) in the hours leading up to sleep.
If you can’t avoid screens entirely, try using a software program or app that filters out blue light.
Install warm-colored LED light bulbs in your lamps to use at night. This can give you enough light to see without disrupting your ability to fall asleep – and it makes sweet mood lighting.
