Asthenopia and visual fatigue are increasingly problematic for much of the population. Increasing demands on vision, tougher competition in schools, universities, and the work place mean people are experiencing unprecedented demands on their visual systems. The closer working distances associated with digital devices and smart phones add to this. So what can we do?
In an evolutionary sense, our visual systems were never designed for prolonged accommodative convergence – we are more suited to the demands of a hunter gatherer, with predominantly distance viewing, relatively relaxed accommodation and minimal sustained near work. Some may say that the current ‘myopia epidemic’ – that we accept is progressing at alarming rates – could in part be an evolutionary development. Consider emmetropic humans who now spend eight to eighteen hours a day accommodating 2.50D at a typical working distance of 40cm. By ‘simply’ becoming -2.50D myopic, the accommodative system no longer has to do any work when performing tasks at this distance. The trade-off of course, is blurred distance vision and a lifetime of potentially progressive myopia and its related risks.
teenagers can enjoy the benefits of great vision indoors and out, as well as protection from the sun
For many people, reducing accommodativeconvergence demand will relieve eye strain and provide for more comfortable vision over prolonged periods. Although simple single vision reading glasses can reduce the demand within a range of near visual tasks, they cannot compensate for someone who looks at a smartphone at 20cm, then switches to a document at 30–40cm, then a computer screen at 60–80cm or a board in a classroom or large lecture theatre. You can see the limitations…
EVOLUTION OR REVOLUTION?
Way back in the 1980s, when we were already starting to struggle with computer vision syndrome and the accelerating visual stresses of modern life, some clever folk came up with an ‘extended focus’ lens, which helped compensate for some of the aforementioned issues. Since then we’ve seen an evolution of specialised lenses, sometimes known as ‘degressive’ or ‘occupational’ lenses. Additionally, we have ‘digital’ lenses, which recently featured in mivision.1 The Sola Access lens, one of the first lenses used as an anti-fatigue lens, was developed and manufactured right here in Australia and launched in the latter part of the 1990s, along with Essilor’s Interview design. This evolved into their branded ‘antifatigue’ lens, which in turn evolved into the more functionally advanced Eyezen lens of today. This is just one example of how lens technology has developed over the past two decades in this category of lens design.
A number of other lens companies have similarly developed successive lens designs to reduce asthenopia in students and young adults who suffer from poor accommodative facility/flexibility, reduced amplitude, and associated convergence issues.
Early adopter prescribers often obtain excellent results with these designs and patients report being able to function and cope much better. For these practitioners it’s a no brainer, but it seems there are still many fence sitters.
The best way to get off the fence is to ask questions of your patients and probe their near visual systems to shed light on current (or potential) issues. Once determined it then makes sense to recommend and prescribe the appropriate lenses and gauge the results.
WHAT ARE THE OPTIONS?
Within an ever-increasing array of antifatigue lenses you’ll find options that range from simpler degressive designs through to progressive lens designs which are suitable for the bulk of our young patients who report asthenopic symptoms. We can also potentially prescribe these lenses as preventative solutions for asymptomatic patients who demonstrate accommodative problems in our battery of tests. Of course, we should also consider vision therapy, in conjunction with prescribing antifatigue lenses, in an effort to improve their underlying function.
Whether these steps are effective at reducing myopia progression is a long debated issue. It seems that at the very least, anti-fatigue lens designs will do no harm and lead to more comfortable, efficient near visual function for most wearers.
There is increasing crossover between anti-fatigue, digital and occupational lens designs. Understanding the optical characteristics of each lens type and the target wearer helps determine which design is the most appropriate choice.
In many cases, the ideal lens design will depend on the wearer’s ergonomic and postural environment, the position and indeed the form of computer they use. For example, a finance specialist or foreign exchange trader with three or four large computer screens – spread out laterally and vertically – is likely to need something quite different from a student who reads books, works on a tablet, smartphone and a 13-inch laptop.
The relevance of ergonomics and postural environment was covered in a recent mivision CPD module Defining near vision behaviour: a tool for practice 2 and is worth reading. As an added bonus you’ll earn two CPD points.
SEE THE LIGHT
The following contributions from our lens partners demonstrate the wide range of options now available.
See the light and get on board with prescribing anti-fatigue lenses. Your asthenopic patients (and others who show signs of potential problems), will likely notice the difference in efficiency, improved performance and less tiredness at the end of a long day. They will surely thank you for your lens recommendation and potentially refer class mates and colleagues, who will not only notice their new look but will also hear about the benefits.
- https://www.mivision.com.au/2019/03/digital-andcomputer- lenses-for-visual-comfort/
- https://www.mieducation.com/defining-near-visionbehaviour- a-new-tool-for-practice/
Lenses to Sharpen Minds
Opticare ClearPro Relax
ClearPro Relax is designed to help reduce the effects of digitally-induced eye strain and near visual stress. ClearPro Relax reduces visual stress when performing near and intermediate visual tasks. It can be prescribed for young myopes and hyperopes. Available upgrades are Blue Guardian, which blocks blue light, and all other UVA and UVB rays to 420nm. Opticare also recommends its anti-glare Skye Multicoat.
Contact: Opticare (AUS)1800 251 852
Shamir Relax is a unique digital designed lens that provides extra power in the lower part of the lens to make viewing close and intermediate tasks easier. Shamir Relax is now available in three viewing shifts 0.50, 0.65 and 0.80, with lens designs suitable for ages between 18–45. Each of the three versions is carefully designed to provide extra support to the eyes for accommodation and additional support for single vision wearers of different ages. Combine Shamir Relax with Glacier Blue Shield coating for protection from harmful blue light.
VSP Unity Relieve
Unity Relieve lenses help single vision patients combat eye strain from device use with a unique design that has the familiar feel of a single vision lens. Using a three-pronged approach to reducing eye strain, Unity Relieve provides unrestricted distance vision, a slight power boost in the near, and targeted blue light defence using TechShield Blue to reduce the symptoms of digital eyestrain and fatigue. Unity Relieve is designed to be easily customised to each patient’s unique visual needs rather than their age group. A personalised fit means better results and a superior patient experience.
Contact: VSP Australia Account Manager
Eyezen from Essilor is designed to relieve ‘digital eye strain’ all day long. Eyezen brings relief with distance vision if needed, plus three different levels of support for the wearer’s accommodation, positioned to stop the asthenopia caused by the closer reading distances used for handheld devices. Eyezen contains the patented Essilor features: light scan technology, which selectively filters 20% of blue-violet light to enhance the contrast of digital screens, and W.A.V.E. technology (Wavefront Advanced Vision Enhancement), an optical design feature which identifies and reduces higher order aberrations to enhance definition.
Contact: Essilor Account Manager
Nikon Relaxsee, part of the Nikon ‘e-life’ series, has two zones: the clear zone dedicated to distance vision, and the adapted power zone for near vision. The adapted power zone of the Nikon Relaxsee Neo gives an accommodation boost of 0.50D, 0.75D, 1:00D or 1.25D for nonpresbyopic patients experiencing eye strain and visual fatigue when using digital devices. All e-life lenses are enhanced with Nikon SeeCoat Blue UV coating for added screen contrast. This combination helps to reduce the stress of daily tasks such as reading and digital device work.
Contact: Essilor Account Manager
Hoya Dynamic Sync
The majority of your patients are looking at digital screens for five or more hours per day, resulting in eye fatigue and digital eye strain. For non-presbyopes there is now a solution: Dynamic Sync single vision lenses provide less eye fatigue and eye strain, relaxed vision in all directions and at all distances, and comfortable, clear vision all day long. Available with two boost add power options, up to +0.53D and up to +0.88D.
Contact: Hoya Account Manager
Zeiss Digital Lens
Zeiss’ Digital lenses allow patients to easily move between their screens and the world around them, with optimum clarity and complete comfort. They provide clear, crisp, comfortable vision all day while reducing eyestrain and minimising the physical strain associated with digital device use. The benefits of the Zeiss Digital Lens are further enhanced with the addition of Zeiss DuraVision BlueProtect. Modern light sources and digital screens emit a high amount of blue light, which can interfere with sleep/wake cycles and contribute to a reduction in visual clarity due to the scattering associated with blue light.
Contact: Zeiss Account Manager
The demands made on our eyes in both the work and home environments mean that our eyes can easily fatigue. Rodenstock Mono Plus 2 is a full back surface digital design single vision lens with a power boost. It is optimised using Listings law for eye rotation at both distance and near, providing remarkably clear vision up to the frame rim. The design will give wide fields of clear vision for less head movement that can be associated with multiple screen use. The choice of a 0.50D or 0.80D boost will give relaxed and fatigue-free vision at near, particularly when using digital devices, such as smartphones, e-books etc. Now available in an extended range +13.00D to -17.00D (1.67 index) and -18.00D (1.74 index).
Contact: Rodenstock (AUS) 02 9748 0988