We are now part of the ‘phygital era’ where the lines between physical and digital living have interlaced to enhance convenience and connectivity. Gone are the days when mobile phones were used just for texts, calls, or the occasional game of Snake; Mobile phones are now our wallets, our communication tool, our entertainment source, and our lifeline in looking busy to avoid awkward social interactions. Yet, many are claiming that these near and frequent interactions with digital devices are causing harm and aggravating eyestrain. How?
Blue light, also known as high energy visible (HEV) light, falls within the visible light spectrum of wavelengths between 400-500nm. It can be additionally categorized into higher energy blue light (400-455nm) where it is deemed to be potentially harmful1, and lower energy blue light (about 460-500nm), which is important in the development of our eyes as well as our general well-being2. (figure 1)
Figure 1. Visible light spectrum and blue light differentiation
While our natural- and largest- source of blue light is from the Sun, we are also exposed to artificial blue light that is emitted from digital devices such as televisions, laptops, mobile devices, and even the fluorescent lights and LEDs that light up our nights!
That said, artificial blue light is emitted differently from our digital devices (figure 2a) compared to natural blue light from the Sun (figure 2b) and peaks around the blue light hazard peak of 435-440nm3,4.
Figure 2a. Artificial blue light emitted from digital devices4
Figure 2b. Natural blue light emitted from the Sun4
Ongoing research has shown that certain wavelengths of blue light are potentially harmful to our eyes although more is needed for conclusive findings, and because blue light is prone to light scattering, it tends to cause glare and visual discomfort that contributes to digital eye strain (DES).
DES refers to a combination of eye and vision problems that are associated with the use of computers and other electronical displays, and some common symptoms include glare, dazzle, uncomfortable vision, pain in or around the eyes, dryness, and eye fatigue5.
There is therefore an increasing trend in people opting for lenses that protect their eyes from blue light to get relief from DES. However, not all blue light blocking lenses are created equal.
ZEISS BlueGuard lenses block up to 40% of potentially harmful blue light (400-455nm), following the ISO-defined limit of maximum blue light phototoxicity to the retinal pigmented epithelial cells1, while allowing beneficial blue light to pass through. Additionally, it provides full UV protection of up to 400nm, in accordance with the definition of UV radiation set by the World Health Organization6.
With the increase of video calls and conferences, more people are also concerned with the reflections of the lenses that are captured by their phones and webcams. This typically occurs with blue light blocking lenses that are layered with a lens coating designed to reflect blue light away.
ZEISS BlueGuard lenses reduce these disturbing blue light reflections by up to 50% as its material absorbs blue light rather than reflect it away, increasing both vision clarity and visibility of your eyes- the difference can be seen easily below (figure 3).
Figure 3. Difference in blue light reflection between blue light blocking coating and material
Equally important to the protection against UV and potentially harmful blue light is the ZEISS BlueGuard lens’ ability to address DES and enable increased overall clarity and comfort, especially when using digital devices. With our eyes being busier than ever, your lenses should complement and enhance your visual performance.
Contact us at here and speak to an eye care professional to find out more on how you can enjoy the ultimate blue light protection and less reflection with ZEISS BlueGuard lenses.
1 ISO/TR 20772:2018-10, Ophthalmic optics – Spectacle lenses – Short wavelength visible solar radiation and the eye.
2 Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV:2019-3.1, The inner clock-Blue light sets the human rhythm – Blue light impact on aging and retinal damage – More facets of blue light.
3 Nikita A. Wong, Hamed Bahmani:2022-2, A review of the current state of research on artificial blue light safety as it applies to digital devices – Electromagnetic spectrum.
4 Eyesafe, What is Blue Light from digital devices? Is it harmful for eyes? – The Blue Light Spike.
5 American Optometric Association, Heathy eyes – Eyes and vision conditions – Computer vision syndrome – Symptoms
6 World Health Organization:2006-4, Solar Ultraviolet Radiation – Global burden of disease from solar ultraviolet radiation – Background – Definition of the risk factor.
APA standard citation
1 ISO/TR 20772 (2018). Spectacle lenses – Short wavelength visible solar radiation and the eye. Ophthalmic optics, 10.
2 Wahl S, Engelhardt M, Schaupp P, Lappe C, Ivanov IV (2019). Blue light impact on aging and retina damage. The inner clock-Blue light sets the human rhythm, 3.1.
3 Wong N.A.,Bahmani H (2022). Electromagnetic spectrum. A review of the current state of research on artificial blue light safety as it applies to digital devices, 2.
4 Eyesafe. The Blue Light Spike. What is Blue Light from digital devices? Is it harmful for eyes?
5 American Optometric Association. Computer vision syndrome – Symptoms. Eyes and vision conditions
6 World Health Organization (2006). Definition of the risk factor. Solar Ultraviolet Radiation – Global burden of disease from solar ultraviolet radiation, 4.