We know we need to protect our eyes from harmful UV rays but what about other forms of light?
Light is made up of electromagnetic particles that travel in waves, varying in length and strength. The shorter the wavelength means the higher the energy the wave emits. Wavelengths are measured in nanometers (nm) and are grouped into gamma rays, x-rays, ultraviolet (UV) rays, visible light, infrared light and radio waves. Together, these wavelengths make up the electromagnetic spectrum.
Visible light is the only part of the electromagnetic spectrum the human eye is sensitive enough to see. These wavelengths are seen as colours; violet, indigo, blue, green, yellow, orange and red.
Where does blue light come from?
Blue light has a wavelength of between approximately 380nm and 500nm making it one of the shortest and highest-energy wavelengths. Whereas ultraviolet light (UV) is largely absorbed by the front of the eye, blue light passes through and reaches the retina. Approximately one-third of all visible light is considered high-energy visible (HEV) or blue light.
It is important to remember that blue light is everywhere, so we are all exposed to some level of blue light during the day. Our bodies use blue light in its natural form to regulate our sleeping and waking cycles, known as our circadian rhythm. It helps to increase our alertness, heighten reaction times and boost our moods. Sunlight is the main source of blue light when we're outdoors, making the sky appear blue, but there are many man-made sources that we can be exposed to.
In addition to the natural blue light from the sun, artificial blue light is emitted from digital screens (TV's, computers, smart phones and tablets) as well as LED and fluorescent lighting. At work, 43% of adults use a computer, tablet or smartphone - as well as during their personal time - for prolonged periods. High exposure to blue light, especially at night time, can lower the production of melatonin (the hormone our bodies use to regulate sleep) which can disrupt our circadian rhythm.
A high level of exposure can sometimes cause us problems with eye strain, headaches and mental and physical fatigue. Prolonged exposure to blue light may cause retinal damage and contribute to age-related macular degeneration (AMD), which can lead to loss of vision.
Digital eye strain and AMD
Studies have shown that too much exposure to blue light can damage our light-sensitive cells in the retina at the back of the eye. This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss. More research is needed to determine how much blue light, whether natural or unnatural, is too much for the retina. Added blue light exposure from computer screens, smartphones and other digital devices might increase a person's risk of macular degeneration later in life.
"Digital eyestrain" is a term used to describe the conditions resulting from the use of electronic gadgets. Many of us spend our time looking at digital screens, whether a computer at work, our smartphone or just relaxing and watching television. Symptoms can include blurry vision, difficulty focusing, dry and irritated eyes, headaches or neck and back pain.
Blue light waves are not as easily focused due to their high energy levels, meaning they scatter. This can reduce contrast when looking at a computer screen and the resultant "noise" can contribute to digital eye strain.
Protective eyewear from uvex
Wearing safety spectacles that reduce harmful blue light is recommended at workplaces with screens as well as for people who work in environments with artificial light sources (LED lighting), for example in light industry or certain logistics platforms.
Safety glasses with uvex CBR65 tint absorb around 50% of blue light, with a maximum absorption of 450 nm, providing protection against harmful blue light and are ideal for use at workplaces with screens.