Blue light protection – a summary of good reasons
The risk of modern light sources
While the light of the „good old incandescent lamp“ is easy on the eye because of the large amount of red and near-infrared wavelenghts in it´s spectrum, modern mercury lights and LED lights are to be used with caution. This includes the back illumination of flat screens and TVs, energy saving bulbs and fluorescent tubes. The biggest concern these days are probably flat screen moitors, as we spend so many hours in our working and private life looking into them, but the negative effect of environmental light with energy saving or LED lamps should not be neglected.
Extremely high amount of blue light in flat screens
Almost all flat screens are now back-lit with LED lights. While white daylight provides a relatively even spectral distribution, LED light has an extremely high proportion of short-wave blue light, and a very low proportion of red lights, which enhance blood circulation and cell regeneration. (see graphic representation)
Damage to the retina
When working on a screen, one looks directly into the light source, so that the radiation hits the macula lutea (yellow spot) directly and unfiltered. The macula lutea is the area of most acute vision, and is located in teh back of the eyeball. While UV light gets filtered out by the eye´s lens, blue light reaches the retina, where it can gradually lead to conditions like age-related macular degeneration (AMD), an incurable condition of the yellow spot which eventually leads to blindness. Numerous studies have linked blue light to the developement of AMD, as blue light radiation leads to the formation of free oxigen radicals, which put the retina cells under oxidative stress, and can amage and even completely destroy cells.
Blue light makes it harder to see clear
Light refraction depends on wavelengths, and the short-wave blue light refracts in an different angle than long-wave red light. So it is focussed on a different level within the eye, which leads to color fringes and blur. This is why pilotes and athletes often like to wear yellow glasses which filter out blue light, thus improving visual acuity and contrast. AMD patients are often prescribed yellow glasses or contact lenses to protect their macula from harmful blue light.
Light refraction within the eye
Disruption in the hormonal balance
Light with a large amount of short-wave blue radiation influences the hormonal system by reducing the production of melatonin (the „sleeping hormone“), and enhancing the production of the „stress hormones“ cortisol and ACTH. This mechanism, which makes sense during the day, can be a serious threat to our health, when we are confronted with too much blue light during the afternoon and evening hours. Disturbances in the hormonal balance can lead to so-called lifestyle diseases like cardiovascular diseases, cancer, diabetes as well as to disorders of metabolism and the immune system.
No chance for regeneration
Red and near-infrared light activates cytochrome oxidase, a central enzyme of the mitochondrial function, which promotes healing and can repair tissue damage on a cellular level. If one spends most of the day under artificial light with a high proportion of blue light and staring into computer or TV screens, the eye gets overloaded with blue light. These light sources usually lack the circulation-enhancing and regenerating red frequencies, and therefore there is hardly any chance for the body to regererate.
Brightness control is no solution
Most screens regulate brightness by pulse-widths modulation, which controls the frequency of light impulses. So when you regulate your monitor to be darker, this only prolongs the pauses between individual light impulses, the intensity of whcih is not changed. So the full charge of the light impulse hits the eye, even when it subjectively seems to be darker. Pulsating signals can be even more harmful to the physiological balance than steady light.
Older LED-lit flat screens and as well as all TFt-screen only cease to flicker at full brightness. If you are using such a screen, we recommend you regulate it to full brightness and protect your eyes with our bluelightprotect filters. Some newer LED-lit screens can be dimmed without causing flickering, in this case dimming might be a good idea. Please note that even with a relatively dark screen a lot of blue light can enter the eyes through wider pupils. Your eyes still need protection, best provided by our bluelightprotect filters.
Safety glasses for your vision
It is logical and nesseccary to use safety glasses when dealing with materials or procedures that can mechanically or chemically damage the eye. But the danger of working on a screen or in a blue light environment with unprotected eyes is widely neglected, even though the damaging machanisms have already been proven in cell experiments. Because the damage accumulates and is chronic in nature, it is quite hard to conduct conlusive „in vivo“ studies (studying the effects of blue light damage on humans). This is why, up to this point, medical evidence strongly suggests, but doesn´t proove the role of blue light in AMD and other medical conditions. If you want to start protecting your vision right now, especially while you work on flat screens, we recommend protecting your eyes with our bluelightprotect safety glasses.