The hazards associated with blue light – and how safety spectacles can help

Smartphone displays, computer monitors, TV screens – artificial sources of blue light are ever-present, both in our everyday working lives and in our private lives. This fact brings a whole range of health risks with it – from tired eyes to retinal diseases – and is confronting us as a society with new challenges. Let’s take a look at the properties and potential hazards associated with blue light, to help us understand what potential eye protection solutions might look like.

In the electromagnetic spectrum, blue light lies in the wavelength range between 380 and 500 nanometres. It therefore falls within the visible part of the spectrum, to which we are exposed every day.

Blue light can be found everywhere – in the natural light emitted by the sun, or in the artificial light emitted by LED lamps or screens (smartphones, tablets, computers, televisions).

Blue light regulates our biorhythm or biological clock. The body uses the natural blue light from the sun to distinguish between day and night and to regulate our sleep-wake cycle. The perception of blue light (approx. 490 nm) stimulates and controls the production of the sleep hormone melatonin.

Blue light is also thought to lift our mood and increase the feeling of well-being.

The shorter the wavelength of light, the more energy it stores. Blue light waves fall within the short wave range of the visible spectrum and belongs to the most energy-rich ones. This explains why blue light (between approx. 380 and 450 nm) is more hazardous than other light. In addition to that the fact that blue (artificial) light emitted by screens has a richer spectrum of harmful blue light than sunlight, which contains more yellow and red.

A further factor raising concern among specialists is linked to a change in our lifestyle, which leads to us being exposed to excessive amounts of blue light. In addition to the natural blue light emitted by the sun, we are confronted with artificial blue light from screens and LED light sources on a daily basis. This phenomenon is further aggravated by the length of time for which we are exposed to this light. At work, 43% of adults use a computer or tablet, as well as a smartphone, for prolonged periods of time.

The energy emitted from blue light causes it to flicker more than other light. It also produces more glare, resulting in eye fatigue and headaches in the long term. Almost 70% of all adults who regularly use electronic devices with illuminated displays report certain symptoms of visual fatigue, such as impaired vision, dry and irritated eyes or headaches.

Especially in the evening, artificial blue light disturbs our biorhythm by slowing down the secretion of melatonin. This explains the significant increase in the number of people complaining of sleep disturbances and suffering from insomnia.

Contact with harmful blue light (between 380 and 450 nm) can lead to age-related macular degeneration. This means that, over time, retinal cells can become irreversibly damaged. In industrial countries, this is the most frequent cause of eye diseases resulting in blindness.