Why not block all blue light all the time?
Some degree of blue light exposure is considered necessary for for good health. Studies have shown the benefits of blue light in relation to regulating circadian rhythm, boosting alertness and reducing seasonal affective disorder.
As it is primarily the lower part of the blue light spectrum operating between 400-450 nanometers which is considered most harmful, allowing exposure to the higher end of the blue spectrum between 450-500 nanometers during the day, is actually a good thing. It helps you stay alert and awake during the day by letting your body know that it is daytime.
After sunset, we recommend reducing exposure to all blue light (between 400-500nm) as this will give your body the signals it needs to prepare for sleep, and encourage the production of melatonin, the sleep-promoting hormone.
This is because what may be ‘good’ blue light during the day, becomes ‘bad’ blue light in the evening, as research has shown that blue light between 400-480nm can suppress the production of melatonin. For evening, we recommend the Swannies Night Glasses (with orange tint) for full spectrum blue light protection.
Is blue light good or bad for me?
This is not a straightforward question and the short answer is: it depends. To understand why, it helps to understand a little more about how blue light operates on the light spectrum.
Blue light is a form of High Energy Visible light (HEV) which operates on the light spectrum between 400-500 nanometers.
The closer the wavelength is to the UV spectrum, the greater the risk of harmful effects to your eyes. This is why blue light between the range of 400-450 nanometers is generally considered ‘bad blue light’. Studies have shown that blue light in this range in particular, may increase the likelihood of age-related macular degeneration.
However, some blue light is good for your health, and arguably necessary. Studies have shown that blue light can boost alertness, help memory and cognitive function and elevate mood, as well as playing an important part in regulating your circadian rhythm.
So how do you get the benefits of blue light without the harmful effects that come along with it? By blocking only the harmful part of the blue light spectrum from 400-450nm, but allowing blue light between 450-500nm to get through, Swannies Day Glasses do just this.
What is blue light?
Blue light is a part of the light spectrum operating between 400-500 nanometers (nm). Blue light is emitted from all artificial light sources including computer screens, TV screens, cell phones, tablets and light bulbs. Although referred to as 'blue light', it may not always appear visibly blue.
Blue light has a very short wavelength, and so produces a higher amount of energy.
Recent scientific studies have shown exposure to the blue light spectrum may cause serious long-term damage to your eyes and suppress the production of melatonin.
Because the human eye is not very good at blocking blue light, it is able to penetrate all the way to the retina (the inner lining of the back of the eye). Laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina. This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss.
What are the sources of blue light?
We are surrounded by blue light every day and sometimes, without knowing. All artificial, electric-powered lighting produced some level of blue light, even if it doesn't look 'blue'.
The most common sources of blue light include;
- Mobile & tablet screens
- Computer monitors
- Flat screen televisions
- Fluorescent and LED lighting
Aside from stopping my body from producing melatonin, what are the other effects of blue light?
Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easy for the eye to focus on. This means that when you're looking at computer screens and other digital devices, this unfocused visual "noise" reduces contrast and can contribute to digital eye strain.
There is also research that suggests that that excessive exposure to blue light, especially at night, can cause negative effects to your health such as several types of cancer (breast, prostate), diabetes, heart disease, obesity, and various sleep disorders.