Spectacle lenses have come a long way since CR39 plastic lenses entered the market in the 1970s displacing glass.
Back then, the arrival of CR39 lenses was welcomed. Crown glass spectacle lenses – the majority of glass lenses prescribed – lacked impact resistance and the ability to block ultraviolet light; with around 84 per cent transmittance of UVA and about 31 per cent transmittance of UVB. However, this was of little concern, as the effect of UV radiation on eyes was rarely considered.
Things have changed – the ‘Slip, Slop, Slap and Wrap’ campaigns run in the Australia/ New Zealand region have been effective and there is now high awareness of the damaging effects of UV and life threatening risk of melanoma – and the need for UV protection.
Plastic lenses have continued to evolve and today the biggest sellers are 1.6 index followed by 1.67 and 1.74. Both untinted and sunglass options block 100 per cent of UVA and B, and all sunglasses legally imported and sold in Australia and New Zealand must comply with 100 per cent UV protection standards up to 380 nanometres (nm).
PERIPHERAL LIGHT FOCUSSING EFFECT
Along with protecting the eyes from direct UV damage, we have become increasingly aware of the need to prevent the ‘peripheral light focussing effect’ (PLFE). 1 PLFE concentrates UV at the sensitive nasal limbus and is linked to development of pterygia and pingueculae (also known as surfer’s eye). Wraparound sunglasses can effectively prevent light from striking the cornea peripherally – something regular or fashion sunglasses often don’t achieve.
UV AND THE OZONE LAYER
The atmosphere absorbs most of the more damaging UVC spectrum, although UVA and B radiation remain a concern, with levels increasing over the past few decades linked to the depletion of the ozone layer.
Although reductions in harmful fluorocarbons have stabilised polar depletion, the ozone layer is thinning in the mid-latitudes. Caused in part by nitrogen based fertilisers, Associate Professor Clare Murphy, School of Chemistry at Wollongong University has explained, “The largest factor involved in mid-latitude ozone depletion is the nitrogen cycle, which operates by nitrous oxide turning into reactive nitrogen in the stratosphere”.
Dr Murphy has stated that nitrous oxide almost stopped the Concord from flying due to concerns about reactive nitrogen in the stratosphere.2 She added that “ozone trends were not fully understood”.
UV AND THE EYE
There is also a lot of confusion, misinformation, and controversy surrounding UV, melanoma, and eye damage. We know that the cornea and lens are able to absorb high levels of UV and very little reaches the retina. However UV light is high energy radiation and every photon that reaches the sensitive macular area of the eye is potentially damaging.
The all-round best advice is to offer maximal UV protection in the UVA and B spectrum. Most spectacle lens manufacturers provide this in their modern plastic lenses. Zeiss has added ‘UV Protect’ technology – which offers full UV blocking all the way to 400nm – coupled with awareness campaigns and marketing to help highlight the importance of UV protection.
BEST PRACTICE
Discussing the importance of UV protecting spectacles, as well as recommending supplementary pairs of wraparound sunglasses to those who spend time working or enjoying the outdoors, can help grow your practice and slice of the pie.
Even fashionistas and social media influencers, who are more interested in the aesthetics of fashion sunglasses than the functionality of protective eyewear, may opt for a secondary wraparound pair if they’re made aware of the need to protect against the PLFE. Once you have them convinced, ask them to spread the word via social media and be sure to do the same using your own accounts.
Check out what’s on offer from our featured sunglass and lens suppliers and make use of what remains of the summer to promote proper ocular sun protection. The coming winter is another opportunity to share the importance of UV protection for those taking to the ski slopes.
References
- contactlensupdate.com/2015/04/21/ultravioletradiation- and-the-eye
- www.smh.com.au/environment/weather/going-to-extremesuv- radiation-is-on-the-way-up-20180308-p4z3cp.html
Lenses that Protect
Crizal Sapphire
Crizal Sapphire UV is the very latest in anti-reflection coatings. Its multi-angular technology takes into account all angles of light striking from the front, the sides, and the back of the lens for best in class transparency. Compared to Crizal UV, side on reflections are reduced 30 per cent and front on reflections reduced by 20 per cent.
Crizal Sapphire UV is endorsed by Cancer Council Australia, and gives E-SPF 35 on all indices above 1.5, further reducing reflected back surface UV. Its pale sapphire bloom, gives amazing clarity and is seemingly invisible on the wearer.
Contact: Essilor Account Manager
Transitions Light Intelligent Lenses
Transitions Light Intelligent Lenses – Transitions Signature, Transitions XTRActive and Transitions Vantage – are everyday lenses designed to be worn both indoors and outdoors. Clear indoors, Transitions automatically darken outdoors enabling wearers to not only reduce outdoor glare but block 100 per cent UVA and B.
The ultimate light protection of Transitions lenses blocks everyday UV while also filtering harmful blue light – the sun being the largest source of harmful blue light emitting over 100 times more than digital devices.
Contact: Transitions Account Manager (AUS) 08 8238 3257
SunSync Drive XT
SunSync Drive XT is an extra-active, light reactive lens that works in the car, activating in response to both UV and visible light. While all SunSync Light Reactive lenses block 100 per cent of UV light, SunSync Drive XT has great in-car colour retention, ultra-fast activation, and exceptional durability. It also has targeted blue light filtration and 100 per cent UV protection from harmful UVA and B radiation, making it the perfect lens addition for use behind the wheel, at home, work, the beach… everywhere.
SunSync Drive XT is backed by a one year, 100 per cent satisfaction guarantee, and is available in both grey and brown in 1.50, 1.53, 1.59, and 1.67 index, in single vision grind and on VSP’s progressive lens range Unity Via, Unity Via Plus, Unity Via Elite, and Unity Via Mobile lenses.
Contact: VSP Account Manager (AUS) 1800 251 025
Zeiss UVProtect
UV rays between 380 and 40 nm are responsible for most UV related eye damage. For this reason health organisations recommend protection up to 400nm. Currently up to 80 per cent of clear lenses globally do not offer full UV protection.
Zeiss UVProtect Technology sets an industry benchmark by offering UV protection up to 400nm in all clear lenses – the same UV protection as premium sunglasses.
While full UV protection is a feature of all Zeiss branded clear lenses, UVProtect Technology is not available on aphal, bifocal and glass lenses.
Contact: Zeiss Account Manager (AUS) 1800 251 025
Hoya
Hoya UV Control coating applied to the back surface of lenses, together with Hoya’s UV resistant lens materials, provide 100 per cent protection against the harmful effects of UV and UV related eye diseases.
UV Control is available in combination with Diamond Finish multi-coat – “the hardest anti-reflection coating available on the market today”, according to Hoya. Its long lasting anti-reflective, scratch resistant, water, dirt and dust repellent properties provide spectacle lens wearers with extra comfort and relaxed, clear vision.
Hoya’s Sensity portfolio, available in grey, brown, and green, reduces glare and provides 100 per cent protection against UV rays. Sensity lenses darken outdoors and quickly fade back to exceptionally clear indoors, ensuring comfortable vision in all climates and seasons. Sensity Dark, a new addition to the family, delivers extra darkness outdoors and darkens behind the car window. Sensity Shine offers the benefits of Sensity Dark and comes with a mirror coating. It’s barely noticeable when unreacted and transforms to a fashionable mirror coated sun lens when in the sun.
Contact: Hoya Account Manager (AUS) 02 9384 2000
Bonastar
Bonastar supplies full UV protection up to 400nm for mid index and high index clear lenses, all blue light blocking, photochromic, Transitions, and polarised lenses.
The company’s new fashion focussed light tinted plano and prescription lenses are ideal for sunny and cloudy days, as well as indoors. They’re available in 20 colour variations, including burnt orange, sky blue, rose pink, lilac, and lemon, and with UV coating they block out 99 per cent of harmful UV rays. Bonastar also supplies classic sun tints with 100 per cent UV protection for medium to bright light conditions.
Contact Bonastar: (AUS) 02 9310 1688
Opticare
Opticare’s Blue Guardian lens blocks high energy blue light from entering the eye and helps prevent the impact of all harmful UVA and B energies. According to Opticare, this lens also helps regulate wearers’ circadian rhythm (the sleep and wake cycle), assists with memory and cognitive function, and elevates overall mood and alertness.
Contact: Opticare (AUS) 1800 251 852
Rodenstock
Rodenstock Colormatic IQ 2, used in conjunction with any of the Solitaire family of coatings, maximises UV and glare protection. Colormatic materials, which stop the transmission of UV light, are available as follows:
Colormatic IQ2 – clear to 85 per cent absorption tints, and Colormatic IQ Sun 2 – pre tinted 50–90 per cent.
Dispensing with any of the Solitaire Protect 2 family of coatings will stop further danger of reflected UV from the back of the lens. Choose Solitaire Protect Plus 2 with X-tra Clean or Solitaire Protect Sun 2 with X-tra clean for sunglasses.
Contact: Rodenstock (AUS) 02 9748 0988
Shamir
Shamir OHS/Eyres safety frames provide 100 per cent UV eye protection. According to Shamir, the Eyres full wrap around safety certified frame design, “is the only safety eyewear that provides absolute UV 400 protection with its front and side ocular/facial coverage and protection. This means it can provide 100 per cent safety from projectile objects and 100 per cent safety from unseen UV rays.”
Shamir free form lenses, (available in a wide range of coatings and tints) are designed to effectively block the sun’s harmful ultraviolet rays. Shamir Glacier Plus UV coating provides double sided UV protection from incoming and reflected light from both the front and back lens surface.
Contact: Shamir (AUS) 1300 553 465
