I have been reading some conflicting reports on Blue Light and whilst in some quarters it is viewed as a hero in assisting our sleep and general health, in others it is judged a villain in causing eye disease. Which is it?
According to Dr Mark Dunbar OD, adjunct faculty member at Indiana University School of Optometry and Salus University College of Optometry, it depends on which kind of blue light because light can be both harmful and beneficial for our vision as well as our overall health.
He explains that sunlight contains between 25%-30% blue light during the day and that as part of the visible light spectrum, blue light reaches deeper into the eye and its cumulative effect can cause damage to the retina. Furthermore, in certain wavelengths, blue light is implicated in the development of age-related macular degeneration (AMD). However light in general and blue light in this case is also essential in helping us see better and regulate our sleep/wake cycle, which in turn helps to maintain and regulate memory, mood and hormonal balance.
Blue Light -The Villain
It is blue violet light that causes damage to the back of the eye increasing the risk of risk of AMD. With the increase in the use of digital devices and modern lighting, such as LED lights and compact fluorescent lamps (CFLs), most of which emit a high level of blue violet light. CFLs contain about 25% of harmful blue light and LEDs contain about 35% of harmful blue light.
Interestingly, the cooler the white LED, the higher the blue proportion. And by 2020, 90% of all of our light sources are estimated to be LED lighting. So, our exposure to blue light is everywhere and only increasing. As the population ages, cataract and macular degeneration cases are increasing . In the United States in 2012, there were approximately 24 million cases of cataracts in people aged 40+, which is a 19% increase from 2000 numbers. For macular degeneration, 2 million people aged 50+ had late AMD in 2012, which is a 25% increase from 2000.
By the year 2050 it is estimated that the cataract population will reach 50 million and AMD around 5 million.
So it is a significant problem and here blue violet light is the villain.
Blue Light – The Hero
However, not all blue light is bad. The labeled blue-turquoise light range, which is from 465 nm to 495 nm, is essential to our vision, the function of our pupillary reflex, and it also helps to regulate our circadian sleep/wake cycle. Inadequate light exposure means inadequate blue-turquoise light, which can throw off our circadian biological clock and our sleep/wake cycle.
This blue-turquoise light can have healthy affects on vision as well as the body, and so here blue turquoise light is the hero.
Protection from the Bad Blue Light
How can we block the harmful blue violet rays of light but allow the helpful blue turquoise rays of light to penetrate through and get into the eye?
Essilor and the Paris Vision Institute have developed a selective light filter or a lens to block the harmful blue-violet light and yet allow the blue-turquoise light and the longer wavelengths of light to continue to penetrate through it.
This light filter is called Light Scan, a patented, selective, noglare technology with three key features:
- it selectively filters out harmful blue-violet and UV light,
- it allows the beneficial visible light, including the blue-turquoise light, to pass through and
- it maintains an excellent transparency of the lens, so there’s no color distortion and you get excellent clarity with the lens.
This new lens technology is based on laboratory studies over a four-year period of time by a high-class group of scientists as well as clinicians who came up with some very important data that allowed them to zoom in on the light that needed to be blocked and the light that needed to get through. So this new lens design really is very specific for more selective light.
Who’s going to need the most protection?
Those who have high exposure to white LED or fluorescent light bulbs in offices and homes, frequent users of LED computer monitors, tablets, or smart phones, and those at risk for AMD, particularly those at high risk, (those with family history, smokers, etc.). Also many companies are working on technology to look at harmful blue light and ways to block that and still allow healthy blue light to remain.
It seems we need to become more informed about the differences between blue violet (villain) and blue turquoise (hero) light and be inquisitive into the lighting in our workplaces and homes and the potential effect it has on us as individuals.
Read Dr Dunbar’s article on ultra violet and blue light