In the electromagnetic spectrum, blue light lies in the wavelength range between 380 and 500 nanometers. It, therefore, falls within the visible part of the spectrum, to which we are exposed every day.
As a part of the visible light spectrum, 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).
The positive effects of blue light
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 regulate our sleep-wake cycle. The perception of blue light (approx. 490 nm) stimulates and controls the production of the sleep hormone melatonin. However, the intensity of the blue light emitted by the sun is substantially lower than the intensity of the blue light frequencies from the artificial light sources.
Blue light is also an essential element to lift our mood and increase our feeling of well-being.
Blue light is hazardous to the eyes
The shorter the wavelength of light, the more energy it stores. Blue light waves fall within the visible spectrum's short wave range and belong 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, 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 exposes us 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 daily. 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 and a smartphone for prolonged periods.