Advances in the technology behind spectacle lenses for myopia provide more options than ever before to correct and maintain vision. The key is to ensure customers are fully engaged in the process of spectacle lens correction so that they realise the value of investing in their vision.
The latest research1,2 indicates that myopia is rapidly increasing in prevalence and will increase sevenfold by 2050. The majority of myopia occurs between the ages of six and 16, potentially impacting social and academic development. Onset is due to a combination of nature and nurture.
In the case of nurture, it has been demonstrated that if one or both parents are myopic, there is a statistically higher probability that the child will also develop myopia. Prevalence is far higher among Japanese, Chinese and Korean children than among children in Europe, the USA or Africa.
However, it is nature – i.e. environmental factors as a result of the changing nature of our lifestyles – that has primarily been held responsible for increasing rates of myopia. This has been identified as resulting from a combination of decreased time outdoors, increased near work activities, and other factors.
The study found thatan extra 40 minutes of outside activity per day over three years led to a 23 per cent reduction in the rate of myopia in six-year-old Chinese children
A study, by Professor of Ophthalmic Epidemiology at the University of Melbourne, Professor Mingguang He from the Centre for Eye Research Australia, reported that myopia had reached epidemic levels in parts of east and southeast Asia. Young adults in these areas are being increasingly affected, with 80 to 90 per cent of high school graduates diagnosed and 20 per cent of these having high myopia (equal to or less than -6 dioptres.)
The study found that an extra 40 minutes of outside activity per day over three years led to a 23 per cent reduction in the rate of myopia in six-year-old Chinese children.
While the exact link between time spent outdoors and better eyesight remains unclear, Professor He and his colleagues propose that this might involve increased dopamine being released from the retina, stimulated by brighter light outdoor.
The increasing prevalence of myopia presents an excellent opportunity to discuss the latest research with your patients, to advise them on the importance of regular eye examinations for children, to inform them of strategies to try to slow the progression of myopia and of new technologies in spectacles lenses available once diagnosis has occurred.
Ensuring children receive a regular eye examination each year is critical to enable early detection and, when necessary, provide intervention to slow the progression of this disease.
Strategies and advice to try to halt the progression of myopia are:
- Spend time outdoors
- Reduce time spent on near based activities including electronic devices that require constant focussing up close.
When correction with spectacle lenses is required there are a number of considerations required:
Hi Index Lenses
Hi Index materials, which allow for differing degrees of thickness and weight, are a great option, particularly for first-time myopes who are conscious of wearing spectacles.
In the case of children, parents need to be involved in the decision-making process. There may be a need to balance budget and appearance. Being able to explain the benefits of high index lenses and the difference the lenses will make is critical if a decision is not to be based purely on price. Features, such as being more cosmetically appealing, lighter and more comfortable to wear are very important to highlight.
Aspheric Lens Designs
Combining Hi Index materials with advanced aspheric lens designs makes lenses flatter with a slimmer profile as well as lighter, and thus more appealing. This, in turn, increases the number of suitable frames that can be chosen, which is especially important when it comes to higher prescriptions. The improvement in clarity of vision is also significant to the wearer.
Children need to be positive about wearing their glasses and the more cosmetically appealing they are, the more likely it is that they will wear them. Anti-reflective (AR) coatings offer aesthetic benefits for myopic lenses while also reducing eye strain and glare from fluorescent lights and screens.
This is increasingly beneficial, particularly for children who often present as myopic and spend extensive amounts of time using digital devices. Blue light blocking, added for adults and children using digital devices, offers another layer of protection and reduces the effects on circadian rhythms.
AR coatings are often combined with superior scratch resistance, which makes lenses more robust and last longer. Additionally, UV protection added to the lens provides further protection against harmful UV rays especially in a child’s developing eyes.
Myopia Control Lenses
A number of companies are developing lenses to reduce myopia progression.
These lenses try to reduce the accommodative lag or reduce peripheral retinal image blur. This is a new area of research and development which will see more effort in coming years.
Today there are many more technological advances in spectacle lenses for myopes which allow a greater range of frames to be worn. These considerations need to be explained and discussed with your patients to ensure they have full understanding and get on board with the decision-making process.
As an optometrist, it is important to remain up to date with the latest research and technology so that you can provide your patients with salient advice and ensure they receive the very best of care for their vision.
Hastings Optical Supplies
The major concerns of moderate to high myopes are mostly related to cosmesis, clarity and restricted frame choices.
Hasting Optical Supplies has sophisticated solutions to minimise these lens issues and allow a choice of larger and more curved frames.
Conventional lens corrections are disadvantaged by thicker and heavier lenses, increased oblique astigmatism and for high index lenses, the greater dispersion caused by their lower Abbe number. This leads to loss of visual clarity and consumer annoyance.
Using freeform production and Digital Ray Path optimisation technology, the oblique astigmatism of high minus lenses is dramatically reduced.
Lenticular lens processing enhances the cosmetic appearance by reducing edge thickness and weight. It also allows the use of a lower index material without greatly affecting the cosmesis. Two lenticularisation methods can be ordered, ‘Smooth Lenticular’ with a user defined optical region or ‘Lenticular Frame Shape’.
Combining Hastings Optical Supplies’ Digital Ray Path technology and lenticular lens processing results in a thinner, lighter and more comfortable lens with enhanced visual clarity.
Myopia lenses are available in single vision, digital bifocal or any of Hastings Optical’s freeform multifocal designs.
Tokai Optical offers a range of high index lenses for the myopic patient that range from 1.6 to 1.76 lens materials.
For high myopes or moderate myopes who want the thinnest lens option, Tokai Optical says its 1.76 lens is ideal. Single and double sided aspheric (1.76 Go) ultra-high index lenses are developed from computer-based simulations and leading-edge design theories to achieve natural vision with minimal distortion and less astigmatic aberration. According to the company, its 1.76 index lens material facilitates the thinnest plastic lens available for high corrections and comes in a range of tint colours and Transitions 7.
For low myopes 1.6 is the ideal choice and for moderate myopes 1.67 or 1.7 indices are available. Both 1.6 and 1.67 indices are available in ‘Lutina’, a new lens material (not a coating) that absorbs the UV and high energy visible light (HEV) up to 420 nm. 400–420nm are the wave lengths that both retinal lutein and lipofuscin absorb, thus by cutting these light waves out, the Lutina lens may reduce oxidative stress and potentially reduce damage to the lutein and macular pigment caused by free radicals.
Contact: Tokai Australia (AUS) 07 3012 9422
Hoya has a wide range of products well suited to the myopic patient, all of which are manufactured from high performing, high index materials. Coatings include diamond finish and materials include Eyvia 1.74, which boasts Hoya’s highest refractive index of 1.74, and is the company’s thinnest plastic material, making it ideal for customers with higher plus or minus prescriptions.
Hoyalux iD MyStyle V+ progressives & Workstyle V+ extended focus lenses respond to the great demand for natural, stable vision in a dynamic, digital world that places high demands on the visual system. Both lenses consider the right and left prescription individually to calculate the required binocular lens design. Patented binocular harmonisation technology ensures the correction is appropriate at each point of the lens, to meet the exact needs of each eye.
Each V+ design is evaluated with Hoya’s binocular eye model, a patented binocular performance measurement programme which guarantees that each design is verified under real life circumstances before it goes into production. This ensures unprecedented binocular performance.
Patients benefit from perfect and effortless focusing, constant stability and excellent depth of vision.
Contact: Hoya Account Representative.
The Seemax lens incorporates Nikon expertise in optical systems to create a lens that delivers what Essilor regards as “unsurpassed” visual performance across the entire surface of the lens as well as providing “unprecedented” surface control by combining nine aspheric optimisation axes. The double-aspheric design of Nikon Seemax is able to “control aberrations and distortions more effectively to ensure wider, clearer and sharper field of vision from the centre to the periphery of the lens” says Essilor.
Contact: Essilor Account Manager
Zeiss offers two distinct progressive lens designs aimed at practitioners who accept that myopia progression in children and adolescents can be contained by managing accommodation required for near vision.
The MC Myopia Control Progressive lens was designed specifically for use with children, delivering a large clear distance, a large clear near, and a short progression between the two viewing areas. MC Myopia Control is a traditional front surface progressive available with a 1.50 addition only.
Recently, Zeiss launched an optically optimised progressive lens ideally suited for use with children, with exceptionally large distance and near zones and compressed intermediate, available with additions 0.50 to 1.25. Priced more competitively than MC Myopia Control, Zeiss Digital for Kids contains an adjustable corridor, ensuring the critical distance and near viewing zones are maintained when fitted into children’s frames.
Contact: Zeiss Account Representative.
Transitions lenses are an ideal choice for myopia sufferers who have selected corrective spectacles as part of their treatment. Designed using the latest cutting edge technology, these high performing lenses are compatible with most prescriptions and virtually any frame design. The Transitions family of products is available in light-weight, high index materials including polycarbonate.
Importantly, Transitions lenses go beyond vision correction to enhance the way we see, adjusting to any lighting condition and filtering glare to ensure we see the best we can all the time.
The Transitions family of adaptive lenses represents the widest range of photochromic lenses with an option to suit every lifestyle. For people who spend most of the day out of the sun such as in the office or at home, Transitions Signature lenses are completely clear indoors. For ‘outdoorsy’ types, Transitions XTRActive lenses provide the darkest tint outdoors and enhance colour perception for a visual advantage in outdoor sports and activities. They also provide a hint of tint indoors to shield against eye strain from harsh indoor light. All Transitions lenses block 100 per cent of UVA and UVB rays.
Contact: Transitions Account Representative.
Jim Papas is an optometrist with extensive experience in contact lenses and an expert in optical retail, business strategy and brand development. Jim has won multiple awards for customer service and commercial innovation, including the 2015 Australian Retail Innovator of the Year award.