Dr. Christian Lappe

We are surrounded by radiation of different wavelengths – the so-called electromagnetic spectrum. Only a very small part of this spectrum is perceptible to humans as visible light. Blue light represents the part of the visible spectrum with the shortest wavelengths between 380 and 500 nanometers.
Blue light is a major component of our daylight. The natural source of blue light is the sun. We are increasingly exposed to artificial light sources such as LED technology or all the displays and screens. All these digital devices emit a lot of blue light.

Blue and especially blue-violet light has very high energy due to the short wavelengths and thus the potential to cause eye-damage. The photobiological risk assessment specifies certain thresholds at which we must classify sources of light. Standard electronic lighting falls below these thresholds by a factor of 40 to 200. This doesn’t apply to outdoor activities. When we spend time in daylight and are exposed to the sun outside, protection from UV radiation and intense blue light is definitely a good idea.

Blue light has a significant impact on our well-being. In addition to blue light, which our eyes perceive as blue color, it’s interesting to know that there are also photoreceptors that aren’t responsible for vision – these pick up light intensities instead. Such photoreceptors are very sensitive to the intensity and presence of blue light. And it’s for a very different process that’s important for humans: They control our circadian rhythm.

Blue light has an influence on human vision. An effect which is also responsible for the sky being blue involves scattering. The scattering depends on the wavelength and blue light is scattered more intensely. The eye produces a certain amount of scattered light, especially at the ocular media through which light passes, called visual noise. You could also describe this as an image in the eye that isn’t seen sharply but instead produces noise. In extreme cases, this can cause a perception of glare or reduced contrast. This is one of the effects where blue light plays a role.

The good news is that there aren’t any studies showing that the shift in the workplace toward working from home and mobile work would cause harm to our eyesight.  We should follow a few simple rules:

• Provide sufficiently well-lit conditions and room lighting. 
• Fresh air and blinking are essential too.
• 20-20-20 rule, which states that, if possible, you should direct your eyes from near work (which is one meter) to a distance of at least 6 meters, or 20 feet, for 20 seconds every 20 minutes.

Sunlight can be pretty dangerous. Many people talk about the dangers of UV radiation when they are in the sun, and this also applies to the eyes. UV rays are everywhere when the sun is out. This is even true in the shade due to the refraction of UV rays.

The simple answer is: There’s nothing we can do about it. This change affects all of us because it’s an age-related change in the eye. Presbyopia is not an age-related farsightedness but the declining ability of our visual system to focus on objects at close distances.