What is blue light?
Light is made up of tiny entities known as photons, which traverse space in waveform, each with a unique length and strength.
The spectrum of light goes from short and powerful to long and weak, and the distance between the peaks of these waves is known as the wavelength.
Long wavelengths equal less energy and short wavelengths equal more energy.
Expressed in nanometers (nm), these wavelengths cover a wide range of colors perceptible to the human eye, from the warm tones of red and orange to the cool tones of blue and violet, including the imperceptible tones of infrared and ultraviolet.
Each wavelength of light possesses unique attributes and practical applications.
Blue light is part of the visible spectrum. With a wavelength ranging from 380 to 550 nm, it has the shortest wavelength and highest energy.
Retinal Damage
Blue light, specifically in the range of 400-450 nanometers, has short wavelengths and carries a lot of energy.
Its ability to penetrate deep into the retina of the eye can cause damage over time, such as macular degeneration, which can lead to vision loss.
Sleep Health
Blue and green light with wavelengths between 450 and 550 nanometers has a significant impact on the brain’s ability to produce melatonin, a hormone crucial for regulating sleep and promoting overall health and well-being.
Blue Light and Melatonin
Melatonin, the “sleep hormone,” is produced by the pineal gland in response to darkness and regulates sleep-wake cycles.
When the sun goes down and the day comes to an end, the body enters its sleep cycle.
The brain responds by releasing melatonin, a hormone critical for regulating sleep and wakefulness.
Melatonin induces feelings of drowsiness and guides us toward deep, restful sleep.
However, exposure to artificial blue light at night disrupts this delicate process: blue light tricks the brain into thinking it’s still daytime, stops melatonin production, and makes us feel more awake and alert, complicating our ability to fall asleep.
Blue light and today's world
In today’s digital age, we are immersed in the blue light emitted by the screens of our smartphones, laptops, and other devices.
This continuous exposure disrupts our natural sleep-wake cycle by signaling to the brain that it’s still daytime, even after the sun has set.
Doing activities such as watching TV or browsing social media only exacerbates the problem, as they contribute to the emission of high levels of blue light.
As a result, the production of melatonin, the hormone responsible for regulating sleep, is suppressed, ultimately decreasing the quality of our sleep and leaving us feeling sleep-deprived and fatigued.
Exposure to blue light at night affects our circadian rhythm, sleep, and overall health.
The image illustrates the variation in blue light emission between different types of bulbs and their consequent impact on melatonin production.
Incandescent bulbs emit negligible amounts of blue light, while LED bulbs (used by most phones) and CFLs emit considerably higher levels, thus exerting a more pronounced influence on melatonin regulation.
Consequently, candles, characterized by their minimal blue light emissions, are presented as a favorable option for night lighting, providing an environment conducive to optimal melatonin production and sleep quality.
Blue light in nature
Not all blue light is bad for us.
Blue light is found both in nature (in the sun) and artificially (in LED lights and digital devices).
Natural blue light, inherent in daylight, differs from artificial blue light by its coexistence with a spectrum of other wavelengths, comprising infrared, red, yellow, orange, and UV rays, collectively referred to as full-spectrum light.
Throughout the day, this colour balance varies: in the morning there is less blue light and more red and infrared, while at midday blue light and UV rays increase.
As sunset approaches, red and infrared dominate again.
This natural interplay of wavelengths, including blue light, plays a vital role in regulating our circadian rhythm, encouraging deep sleep and holistic health.
In the morning, exposure to natural blue light signals to the brain that it’s time to wake up, promoting alertness and vigor.
This synchronization of our internal clocks is essential for a healthy sleep-wake cycle.
In addition, exposure to blue light increases the production of neurotransmitters, such as dopamine and serotonin, which regulate mood and well-being.
How to optimize your lighting environment?
Getting outdoors in the morning
Exposing yourself to unfiltered natural light upon waking up in the morning is crucial for regulating the body’s circadian rhythm.
This exposure suppresses the release of melatonin, allowing the body to produce more at night, which promotes better sleep quality.
Additionally, exposure to sunlight in the morning can boost energy levels and lift mood, making it a vital component of a healthy daily routine.
Use lighting without blue light
Reduce artificial sources of blue light by replacing your home’s conventional bulbs, which are high in blue light, with sleep-enhancing bulbs and red bedside lamps scientifically designed to eliminate all blue light from your home.
This is very important, as our skin also has light signal receptors that are also affected by artificial light.
Wearing computer glasses during the day
Protect your eyes during the day by wearing computer goggles specifically designed to filter out harmful blue light emitted by screens and artificial light sources.
This can help relieve digital eye strain, headaches, and blurred vision caused by prolonged screen time and exposure to bright light.
