Have you ever wondered why the classic aviator glasses have yellow lenses? This has to do with the special properties of light of different colors: Depending on the wavelength, light is refracted to different degrees, with blue having the largest angle of refraction. This effect also occurs when light enters the vitreous body of the eye, and causes different colors to focus at different planes in the eye. This results in blurred color fringes, which are minimized by filtering out blue components (i.e. yellow lenses).
This simple relationship explains why blue light filters always increase visual acuity and improve contrast perception. This effect is not only used in our driving glasses, it also supports the visual comfort of the screen glasses.
At traffic lights, bicycles or construction sites, you can see red, green or yellow lights. Blue, on the other hand, is for ” Attention!” But having emergency vehicles of the police, fire department or paramedics warn with bright blue lights is by no means for the reason that it would be seen particularly well. The exact opposite is the case: of all the wavelengths of visible light, it has the physical property of scattering the most in the atmosphere. This makes it very difficult to see from higher altitudes and was therefore advantageous for military reasons.
However, the same property makes blue light an inferior light for human vision. Not only is it more refractive than red light, but it is focused at a different plane in the eye, resulting in color fringing and blurring.
For this reason, pilots and athletes often wear yellow glasses, which filter out the blue components and thus increase visual acuity and contrast. Retina-damaged patients are also
often prescribed yellow glasses or contact lenses to protect the macula from damaging blue light.
It is all the more unfortunate that we now have to spend most of our time reading and working in the blue light of our LED screens and LED lamps.
Bildschirmbrillen mit Blaulichtfilter, die für das Arbeiten am PC empfohlen werden, würden angeblich keinen großen Mehrwert bieten. So lautet das Ergebnis einer Übersichtsstudie der Cochrane-Vereinigung,
Die PRiSMA® BluelightProtect LiTE95 Filtergläser sind mit einer Blaulichtfilterrate von echten 95% im Bereich von 400 bis 500 Nm als der UNIVERSAL-Filter zu bezeichnen. Er