Digital devices have taken over our lives. Today, nearly all Australians own either a smartphone or a tablet and nearly 80 per cent of 25 to 40-year-olds own and use at least one digital device.1 It’s true to say most of us would be utterly lost without our digital devices – yet we are only just beginning to understand their potential impact on our vision and well-being.
A recent study conducted by the Vision Council in the United States reported nearly 70 per cent of all adults using digital devices experienced some form of digital eye strain.2 This finding was further collaborated by a three-year study conducted by the Hong Kong Polytechnic University on the health effects of digital devices,3 which found 70 per cent of adults and 30 per cent of children and adolescents have reported musculoskeletal symptoms in different parts of the body in relation to the use of digital devices.
The most commonly reported forms of digital eye strain include: red, dry or irritated eyes, blurred vision and eye fatigue. Recent studies show overuse of digital devices may lead to back, neck and shoulder pain as well as headaches.4 The frequent small print and pixelated images can sometimes be extremely difficult to read, causing the eye to strain in order to focus. Additionally, the ergonomics of how weuse digital devices are different to how we use computers or how we read traditional media such as books or newspapers.
The market has attempted to address the issue of digital eye strain with the introduction of anti-fatigue lenses, starter or pre-presbyopic progressives and enhanced single vision lenses. However, these products have not been widely adapted – they only assist people who currently require some form of prescription or vision correction and do not necessarily assist the most at-risk demographic. Furthermore they do not address the changing behaviours and ergonomics of the digital device user.
…commonly reported forms of digital eye strain include: red, dry or irritated eyes, blurred vision and eye fatigue…
Another hotly debated topic within the ophthalmic lens industry is the impact that blue-violet light, also known as High-Energy Visible (HEV) light emitted from digital devices, has on digital eye strain. It has been speculated that HEV can affect circadian rhythms and lead to vision problems such as cataracts and aged related macular degeneration.5,6 Dr. Joshua L. Dunaief, Associate Professor of Ophthalmology at the University of Pennsylvania’s Scheie Eye Institute who has studied this effect, said “I have not seen any conclusive evidence that levels of light you expect to see from a computer would cause eye damage”. However he added, “we do not know that exposure to bright computer screens or light on sunny days over many years is without risk.”7
To date, there has been no conclusive research showing what levels of HEV is emitted by screens and their impact on living people.
Back to the Drawing Board
A recent study conducted by Zeiss Vision Care in Germany found respondents who used anti-fatigue lenses and enhanced single vision lenses as a solution to deal with digital eye strain had a very low satisfaction rate of 21 per cent.8 This prompted vision scientists at Zeiss to go back to the drawing board, to research how people actually use digital devices and determine the exact issues that needed to be considered in developing a solution that creates better wearer satisfaction. Additionally, examining how optometrists currently refract and prescribe was key to coming up with the solution.
Figure 2a: The Zeiss Digital Lens helps the eye to focus more easily, giving stress and strain-free viewing throughout the day.
Figure 2b: The Zeiss Digital Lens helps the eye to focus more easily, giving stress and strain-free viewing throughout the day.
Figure 3. The ability of the eye to bring objects at near into focus decreases with age, eventually resulting in blurred near vision, eye strain, and other symptoms, once adequate accommodation is no longer available.
Figure 4a. Unlike semi-finished progressive lenses, every Zeiss Digital Lens is optically optimised for the exact prescription in order to provide consistently wide, symmetrical viewing zones to every wearer,
Figure 1. The visual limitations of mobile devices, including reduced text legibility and a short viewing distance, may exacerbate symptoms attributed to overexertion of accommodation and convergence.
Figure 4b. Unlike semi-finished progressive lenses, every Zeiss Digital Lens is optically optimised for the exact prescription in order to provide consistently wide, symmetrical viewing zones to every wearer,
The study also found that most complaints of digital eye strain were reported by those who do not currently wear any vision-correction lenses. Furthermore, digital device users usually hold their devices approximately 30 cm from their eyes, much closer than when viewing or reading traditional media. (Figure 1, 2a and b)
Designing the Preferred Solution
Zeiss vision scientists considered this behaviour, in conjunction with Duane’s standard curve of accommodation, and specifically designed the world’s first lens to meet both the visual and the ergonomic needs of digital device users. The solution provided by Zeiss was reported to reduce the symptoms of digital eye strain by a factor of four and was rated as the preferred solution for digital eye strain with satisfaction levels at 90 per cent when compared to anti-fatigue lenses, starter progressives or enhanced single vision lenses.
This solution for the digital world we now live in is not only suitable for current spectacle lens wearers but is also designed with emmetropes in mind. The Zeiss Digital Lens has been specifically designed for those aged 25 to 45 who may or may not wear spectacles. It is proven to provide the greatest benefit to those aged 30 to 45.9
The Zeiss Digital Lens is designed with an extremely large distance zone to match the visual behaviour of emmetropes and single vision lens wearers. Providing unrestricted distance vision, free from blur and distortion ensures users will not notice any difference at all. Most people aged 25 to 45 have sufficient ability to accommodate for immediate vision, it is therefore important to allow for a comfortable transition to the “digital near zone”. The “digital near zone” in the Zeiss Digital Lens is where the users are able to enjoy using their digital device for longer and experience a significant reduction in digital eye strain. The “digital near zone” can be ordered with a near power starting from 0.5D to 1.25D. Combined with unrestricted distance vision, it ensures comfortable vision all day long.
Furthermore, the Digital Lens incorporates Zeiss FreeForm Lens Technology. Vision scientists at Zeiss Vision Care tested the efficacy of Zeiss Digital Lenses among 49 pre-presbyopic subjects. Of those, 41 subjects experienced eye fatigue at the end of the day with their habitual correction. However, after two weeks of wearing Digital Lens, 46 per cent of the symptomatic subjects no longer experienced eye fatigue. Differences in accommodative facility were also evaluated. On average, subjects were able to alternate fixation from near to far 46 times in two minutes with Zeiss Digital Lens, compared with only 25 times with their habitual correction (p < 0.01). This represents a significant improvement in accommodative facility.
HEV Light Penetration
The current anti-reflective coatings minimise a small amount of HEV light penetration when compared to standard anti-reflective coatings. However, research10 by Zeiss shows that a photochromic lens like PhotoFusion or dedicated tinted lenses with polarisation is more effective at blocking HEV light. For example, a Zeiss Digital Lens with PhotoFusion is able to block nearly double the amount of HEV light indoors and is seven times more effective outdoors when compared to current HEV blocking anti-reflective coatings. The Zeiss Digital Lens with PhotoFusion is possibly the most complete solution for those who regularly use digital devices and who are concerned about the impact of HEV light on their
long term eye health.
Zeiss will be working on a campaign to help educate digital device users on the impact of digital eye strain. The company has launched two apps, with one designed to help eye care professionals conduct a digital eye strain test during the consultation process and one designed for consumers to learn more about digital eye strain themselves. The Zeiss Digital Eye Strain app is available both on iTunes and Google Play. For the ECP version please contact your Zeiss Representative.
The Zeiss Digital Lens will be available later this year.
Andrew Lin is the Product Manager for ZEISS Vision Care Australasia, and has keen interests in digital eye strain, myopia control and using new technology to improve eyecare and refraction in optometry.
References
1. Australian mobile device ownership and home usage report 2014 by Deepend
2. www.thevisioncouncil.org/content/digital-eye-strain/adults
3. The Hong Kong Polytechnic University. (2013, September 5). Health effects of using portable electronic devices studied.
4. Ergonomics, musculoskeletal disorders and computer work, Occupational Medicine 2005;55:168-176
5. Arendt J and Skene DJ. Melatonin as a chronobiotic. Sleep Med Rev 2005;9:25-39
6. Grimm C, Reme CE, Rol PO, Williams TP. Blue light effects on rhodopsin photo reversal of bleaching in living rat eyes. Invest Ophthalmol Vis Sci 2000;41:3984-90
7. www.nbcnews.com/health/health-news/read-it-blink-70-percent-report-digital-eye-strain-n6576
8. Data on File
9. Data on File
10. Data on File
