Many of us now live in a world where we have 24-hour access to electricity. On the other hand, studies increasingly show that evening blue wavelength-rich light exposure might harm sleep quality. Blue light is not just from smartphones, computer screens and tablets; it's also quite prevalent in normal light bulbs.
In our contemporary world, it is almost impossible to get by without artificial lighting at night. Managing the quality and amount of light exposure during evening hours helps us to reduce the effect on our internal systems and circadian rhythm.
What precisely is blue light?
Contrary to our instincts, blue light does not always seem blue since it can be combined with other hues. Made up of several wavelengths across the visible spectrum, "the colours of the rainbow," light is a mix of these wavelengths that produces certain impressions in our eyes that we see as colour.
which, despite its white hue, is thought to be rich in blue light:
You will notice a notable variation in the relative quantities of blue wavelengths between natural daylight and incandescent bulbs. Specifically, the wavelengths that are typically deemed "blue" fall between 430 nm and 530 nm.
When discussing blue light or "blue light hazard" in relation to circadian health, one should understand that any light with a high ratio of blue wavelengths can affect sleep and circadian control.
The following is the spectral power distribution of a white LCD screen usually found in tablets, smartphones and computers:
Once more, the blue wavelengths show a notable blue "peak." Though your smartphone screen may seem white to you, you are getting notable doses of blue light blended in.
The effects of blue light on sleep and melatonin
Though studies have only lately concentrated on the non-visual role of our eyes, we have known for decades that cone cells in our eyes enable us to see. Particularly, studies have revealed a fourth pigment in our eyes known as melanopsin. Though it may not be useful in our eyesight system, this pigment is believed to be a receptor that can indicate melatonin synthesis or suppression, the hormone controlling sleep and wakefulness.
Specific light wavelengths activate melanopsin, which is most sensitive to wavelengths at and around 480 nm, or in layman's terms, mostly blue wavelengths.
Melanopsin receptor in our eyes absorbs blue wavelength light, which reduces melatonin synthesis and therefore promotes alertness. Put another way, melanopsin is the direct connection between blue light's influence on whether we feel alert or drowsy.
During daylight hours, melatonin suppression is good and natural since it increases daytime alertness and helps to preserve our circadian rhythms.
You might have gone through this personally; if your window shades are still closed, you may find it significantly more difficult to get up in the morning.
Then, after sunset, our bodies usually start generating more natural melatonin, a signal to the body that it's time to start considering sleep.
But with artificial lighting, we still get doses of blue-rich wavelengths during evening hours. Though we might be physically exhausted, our melatonin levels stay lowered, which makes it hard to fall asleep.
How can we reduce blue light exposure?
Light in the evening is a required and essential component of our modern life. Like with many health-related concerns, moderation is essential.
Reducing total blue light exposure can be helped by limiting use of tablets and smartphones during evening hours as well as lowering the screen's brightness. Different programs and applications can also assist move the light spectrum away from blue-rich wavelengths.
Reducing the brightness and intensity of light bulbs in your house can also help to lower blue light exposure.
Though, visually demanding tasks like reading should not be done in low brightness since this might worsen eye weariness.
No one enjoys compromise, and you might be asking if there is a method to keep a higher brightness level while also reducing the quantity of blue light.
There surely is, and the M/P ratio is the ideal tool to gauge how far this is feasible. The M/P ratio analyses the spectral power distribution of a light source and contrasts the relative ratio between its influence on encouraging alertness and its influence on generating beneficial visual illumination.
So, a low M/P ratio light source generates less light energy to keep us awake but more light energy to benefit vision.
Look for one with a lower M/P ratio if you want light bulbs that offer enough brightness with little blue light that disturbs sleep.
Because the intensity and duration of general blue light exposure are more important, there is no strict definition of an acceptable M/P ratio for a nighttime light bulb.
That is, if you used the light very close to your face for many hours, a low M/P ratio on a light bulb would not make you immune to the consequences of blue light.
So, when evaluating M/P ratios, a relative comparison is more significant. Natural daylight has an M/P ratio of 1.10; incandescent bulbs have an M/P ratio of 0.55.
Assuming the same positioning and use time as a 40W incandescent bulb, the Lux24 bulbs would have a roughly 30% decrease on total blue light exposure.
Circadian LED Lights
Your blue light exposure can be greatly influenced by your choice of light bulb, particularly in a bedroom and bedside table lamps. With no regard for circadian consequences, standard light bulbs are made merely to generate the most brightness with as least expense possible.
Look to see whether the M/P ratio is stated when looking for LED bulbs that minimise circadian influence; if feasible, check the real spectral power distribution to find the blue light level in the spectrum.
Shenzhen Benwei Lighting Technology Co., Ltd was established in 2010. It is a national high-tech enterprise integrating design, R&D, production and sales of indoor and outdoor lighting products and also can do OEM ,ODM .For more details about our offerings, please contact us at bwzm18@ledbenweilighting.com
