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Presenting new technologies and
advancement in spectacle lens materials
CET approved C-36183
For Trivex Lens Specialist Practices, UK
Harder, stronger, clearer.
A live webinar presented by the ABDO College in Canterbury, UK in association with PPG Optical Materials
Dora Plisic
Trade Manager
PPG Optical Materials
Kevin Gutsell
FBDO (Hons) SLD
ABDO
Keith Cross (guest speaker)
Director, Rx Technologies, R&D PPG
Optical Materials
• Introduction
• Timeline of lens material technology developments
• Overview of lens materials technologies
• Lens material properties and patient benefits
• Developments in lens design and coating technologies
• British consumer trends
• Summary and Q&A
Course Outline
How has technology overall
evolved over the last 60 years?
1937 1977 1983 1991 2001 2007
2G: 1st GSM network
3G: 1st country to launch - UK
Technology Evolution: The Telephone
Technology Evolution: The distribution model
2 years contract with mobile phone network providers
New contract is signed
New mobile phone platform
is provided
How has technology in the ophthalmic lenses evolved over the last 60 years?
Anatomy of an ophthalmic lens
Patient
comfort
Technology Developments in Lens Materials
1950’s CR-39® lens development
begins
1970’s FDA impact test regulation
increases use of CR-39®
lenses 1980’s
2000’s Trivex® lenses introduced
Prescription Distribution
85% of Rx’s in Western Countries are
in the range of +/-3.00 D
Polycarbonate lenses become
more popular in U.S.
Technology Developments in Lens Materials
1980’s
1990’s Additional developments in high
index lenses (1.60, 1.67)
Mid Index (1.56, 1.60) lens
development begings
Prescription Distribution
In the Pacific region, prescriptions are
higher from +/-3.00 to +/-6.00 D
2000’s Very high index lenses
development (1.74)
What is a lens material made from?
Lens material overview: CR-39®
Chemistry
•Organic (Carbon-based)
•Properties:
• Impact resistance better
than glass
• High resistance to heat
• High Abbe number
• Lighter than glass
Structure
•Thermoset
•Highly cross-linked
Lens material overview: Polycarbonate
Chemistry:
•Organic (Carbon-based)
•Properties:
• High Impact resistance
from 90° angle only
• Low resistance to heat
• Low Abbe value
Structure:
•Thermoplastic
•Long independent chains
•Not cross-linked
Lens material overview: High Index
Chemistry:
•Organic (Carbon-based)
• Urethane backbone with added sulfur to
increase refractive index
•1.60: approximately 30% sulphur
•1.67: approximately 40% sulphur
•1.74: approximately 60% sulphur
•Properties:
• Thinner lens
• Lower optical performance
• Higher density
Structure:
•Thermoset
•Highly cross-linked
Lens material overview: Trivex®
Chemistry:
•Organic (Carbon-based)
•Urethane backbone enriched
with Urea (Nitrogen)
•Properties:
• High Impact resistance
• High Resistance to heat
• High Optical performance
• Lightest prescription lens
material
Structure:
•“Quasi-Thermoset”
•Slightly cross-linked long
chain structure
How does this translate
to the overall performance
properties of the lens?
Patient
comfort
60
50
40
30
1.74
(33)
Trivex
(45)
CR-39
(58)
1.67
(31) Polycarbonate
(30)
1.60
(40)
Clearest
17
Clear Vision: Abbe Number
The Abbe Number (V-value) is a measure of the dispersion exhibited by the material. The higher
the Abbe Number the more accurately a lens aligns the spectrum of light waves that pass through
it.
Heaviest Lightest
Trivex 1.11 g/cm3
Polycarbonate
1.20 g/cm3
1.60
1.30 g/cm3 CR-39
1.31 g/cm3
1.67
1.36 g/cm3
1.74
1.47 g/cm3
1.10
1.20
1.30
1.40
1.50
Lightweight: Density
Density expresses the weight of the material. The lower the density, the lighter and more
comfortable the lens will be for the patient.
Thin: Refractive Index
1.65
1.60
1.55
1.50
1.70
1.75 High Index
1.74
CR-39
1.50
Polycarbonate
1.59
High Index
1.67
Mid Index
1.60
Trivex 1.53
Refractive index is the ratio of the velocity of light in vacuum to that in the material. It tells
us how fast light travels through a material.
Ultra violet (UV) radiation is known to cause skin cancer and protection of the eyes from UVA and UVB is considered essential for every patient.
Eye Health: UV Protection
400
390
380
350
High Index
1.74
CR-39
1.50
High Index
1.67
Polycarbonate
1.59
Mid Index
1.60
UV cut- off
(nm)
Trivex 1.53
21
Brittle Resilient
Polycarbonate
>700 in-lbf
1.60
53 in-lbf CR-39
31 in-lbf
1.67
56 in-lbf
300
200
100
0
>700 Trivex >700 in-lbf
Safety & Protection: Durability
How do these features
translate into patient benefits?
Lens is not one feature it is the combination of the features to insure patient comfort
Patient Comfort •80 percent of what children learn in their first 12 years comes through their eyes
• UV levels are three times greater in summer than winter • 20% of cataract cases are due to UV rays • The most of UV damages to eye happen prior to the age of 12 as the eye is not mature and fully protected against UV
• Rimless frames require durable lens that wont break or crack
• Seniors have aging and thinner skin on their nose
• 64.5% of adults are physically active
Potential benefits to ECPs
HIGH END
MID-RANGE
BASE / ENTRY
ADC / CR-39® Global
Trivex®
1.56 Mid-Index
Asia
Polycarbonate US
1.60 High-Index Europe 1.67 High-Index
Europe & US
1.74 High-Index
Europe & US tribrid™
Lens materials positioning
DIOPTRES 0.00 +/-3.0 +/-7.00
Knowledge is power
• Understanding the patient
– Understanding patients needs
– Understanding patients lifestyle
– Understanding patients expectations
• Repeating the benefits of recommended lens
• Educating patients about lenses
• Using regular mailings to keep in touch with the patient.
Lens materials - market share UK
HIGH END
MID-RANGE
ENTRY
0,58%
20,12%
3,6%
1,80%
73%
Source: Strategy with Vision, market data for Y2011
Lens design - market share UK
21,32%
11,27%
67,41%
40%
60%
Source: Strategy with Vision, market data for Y2011
HIGH END
MID-END
18,80%
20,30%
Lens coatings - market share UK
17,40%
43,40% ENTRY
Source: Strategy with Vision, market data for Y2011
Have our dispensing trends
evolved with the technology?
HIGH END
MID-END
18,80%
20,30%
To summarize - market share UK
23,72%
73%
ENTRY
40%
0,58%
60%
60,80%
11,27%
Source: Strategy with Vision, market data for Y2011
Consumer trends
• Britain has become a gadget-obsessed nation, watching more television
online, spending more on internet shopping and using smartphones and
tablets to access the web more heavily than any of the world's leading
economies, according to new research.
• The British love of the latest devices has even seen the UK overtake Japan in
mobile internet use, according to the report from media regulator Ofcom,
which compares data across 17 countries, including the US, China, India,
Russia, Brazil, Ireland, Sweden, France and Germany.
• Mark Sweney
• The Guardian, Thursday 13 December 2012
UK is becoming one of the worlds most web and gadget obsessed countries according to the
latest survey results from Ofcom's annual communications market report.
• Britons are biggest online shoppers in developed world
• Britain is the biggest online shopping nation in the developed
world, with almost two-thirds of adults using the internet to buy
goods or services.
• By James Hall, Consumer Affairs Editor
• 2:17PM GMT 01 Feb 2012
PATIENT COMFORT
Questions and Answers from live Webinar
ABDO College, 30th April 2014
Q: With regards to Tinting Trivex lenses I understand there can be concerns with
A/R consistency, pinholes and bubbling. Has this now been resolved in 2014? Does
tinting affect impact resistance?
A: Trivex lenses tint best when combined with a tintable hard coating as the tint is
more readily absorbed into the coating. Trivex material itself can be difficult to tint
but again if combined with the proper tintable hard coating it may be able to be
tinted. As far as compatibility with AR coating – Trivex is compatible with all AR
coatings and no manufacturers have reported any issues or problems. Any
“bubbling” or “pinhole” defect is most likely related to the tinting process and the
lens not being tinted properly. When tinting Trivex and then applying an AR
coating – labs generally have to over tint the lens as some of the color is removed
during the AR process so in order to match the requested color labs often times
have to add more color than needed and gauge the amount the will be released
during the additional processing and sometimes because of this the lens may be
tinted more than once and this could affect the tintable hard coating so any
defects seen would be a result of the tinting process and note specifically related
to the Trivex material. Tinting does not affect impact resistance.
Q: I was surprised to hear that the UV blocker wears off. How would I explain to my
patient that it wears off and cannot be replaced if lenses are still in good condition
and prescription has not changed, and it cannot be replaced. Therefore not
protecting the eye from UV.
A: Whether or not the UV protection can be replaced is dependent on what other
coatings are on the lens – if it is a lens with no other coatings than it may be able
to be re-applied. I would mainly be concerned with CR-39 or plastic lenses with
no other coatings except the UV absorber – In other lenses and coatings the UV
protection is part of the lens and should not wear down. With CR-39 or plastic
lenses in which a UV dye was used – this is the case where as it may wear off
over time or reduce its efficiency. In these cases I would simply ask the customer
to come back every 6 months to have their glasses re-checked for proper
absorption efficiency
Q: How long does it take for the UV coating to decrease to a level that it becomes
ineffective?
A: UV coatings or dyes can wear off over time but it is dependent on many
conditions such as amount of exposure to UV, environmental issues, types of
cleaners or solvents used etc…Unfortunately there is no specific answer to this so
I would recommend asking customers to bring back their glasses to have the UV
absorption re-tested and validated periodically – perhaps every 6 months.
Q: With relation to Trivex lenses, is there any drop off in UV protection over time as
there is with UV coatings?
A: Trivex lenses have UV protection build in the material/monomer. That means
lenses are produced/cast with the UV protection and therefore it won’t change
over time. Trivex lenses will maintain the UV protection over the intended life of
prescription spectacles. UV protection decreases over time only if it is added to
the lens through a coating, which is not case with Trivex lenses.. Any lens material
with UV protection built in should be fine over the life of the prescription –
approximately 2 years or so. As with anything, there are so many factors that
could contribute to a reduction in the efficiency of the protection but again there
shouldn’t be any issue with the effectiveness over the life of the prescription and I
would say this is the case with all lens materials with UV protection built in.
.
Q: Can you clarify the best materials for rimless glazing - given that many
manufacturers will recommend Polycarbonate as the material of choice even
though it has poor optical performance, Is Trivex material more suitable for rimless
glazing than 1.6, 1.67 or 1.74?
A: Trivex material is considered one of the best materials for rimless glazing given
the exceptional impact- and chemical-resistant features of the material as well as
its outstanding optical performance. Trivex lenses are extremely durable and
tough enough to withstand the stress associated with rimless spectacles, resisting
cracks and fractures to which other lenses are sometimes susceptible. For
patients with stronger prescriptions, lens materials such as 1.60 and 1.67 can be
used for thinner lenses in rimless spectacles, but they may not be as resilient as
Trivex lenses.
.
Q: Safety Specs: Forgive me if I am out of date on Safety specs! Not an everyday
dispense but, given that Trivex material comes via Apache Helicopters (reasonably
safe then!) should we as a profession, be suggesting to safety labs that Trivex
lenses be dispensed in preference over Polycarbonate insofar as impact-
resistancy?
A: Trivex lenses should definitely be considered for safety applications. Trivex
lenses and polycarbonate lenses feature similar impact resistant performance
properties and may be considered equivalent with regard to impact protection.
However, polycarbonate lenses are not as chemically resistant as Trivex lenses
and can also be susceptible to stress-cracking.
.
.
Q: Dispensing children and sports goggles. Are you confident that the material is
as good as safe polycarbonate?
A: Trivex lenses should definitely be considered for children and sport goggles.
Trivex lenses and polycarbonate lenses feature similar impact resistant
performance properties and may be considered equivalent with regard to impact
protection. However, polycarbonate lenses are not as chemically resistant as
Trivex lenses and can also be susceptible to stress-cracking. In addition to the
durability, Trivex lenses offer optical clarity close to CR-39 lenses, while
polycarbonate lenses have the lowest Abbe value of all lenses.
.
Q: What thickness should the material be to consider it safe?
A: Trivex lenses can pass the most stringent spectacle impact performance tests
at . (Note that coatings may alter the impact resistance of any lens material.)
.
Q: It's a great alternative to CR39 but how about thickness? Lots of patients even
as low as -3.00 want their lenses as thin as possible.
A: While patients say they want their lenses as thin as possible, opticians should
recommend a lens with the best overall performance. A combination of optical
performance, lightweight comfort, durability, UV protection AND thinness should
be the preferred recommendation for every patient. For example, consider a -3.00
D prescription – lenses made from Trivex material will be relatively equivalent in
thickness to a 1.60 lens and less than a bank card thicker than a 1.67 lens. Your
patients may not notice the difference in thickness but they would benefit from
improved optical performance, comfort and safety. If they could notice the
difference, they may be willing to accept a slightly thicker lens for the improved all-
around performance.
.
Q: Do you feel that as UK Opticians (DO's & Optoms), we can get blinkered in our
thinking and openness to new products and technologies?
A: Understandably there are a plethora of new lens products being launched on to
the market almost weekly (it seems). When you break this down into specifics of
design, material and coatings we see that very few new materials or concept in
materials has been launched for some years now. And in the past newer materials
have almost entirely been aimed towards lenses being thinner and to some
degree lighter. Much of this happening though at a time when frame shapes and
sizes have not necessarily required higher and higher index! Fortunately the
growth in rimless has meant tensile strength and brittleness has been 'front of
mind'. Polycarbonate and Trivex allow those whose prescription demands a lower
index yet the rimless requirement is different. The 'issue' as I see it is that
generally we recommend lens index simply on the basis of prescription and frame
size. We need to break this habit. This webinar has succeeded in getting people
talking about new technologies and it is this education and training which allows
the optician to comfortably detail and discuss with patients the benefits
.
Q: What are 1.76 lenses? Are they plastic? What is double aspheric?
A: 1.76 lenses are plastic lenses with high sulfur content (approx. 60%) to
increase the refractive index. “Double aspheric” refers to the geometry of a lens in
which the surface has been flattened in two axes (or meridians).
.
Q: Surely the overriding issue for use of new materials like Trivex will be cost -
recent Hi-index lens market growth will be due to huge cost reductions in recent
years.
A: Yes, it is true that cost certainly plays a significant role in the acceptance and
use of any new lens technology – including materials, designs, coatings and
treatments. However, the price of Trivex lenses today is more competitive with
other premium materials. In fact, Trivex lenses are less expensive than 1.67 and
1.74 lenses but offer a more complete set of benefits for patients with low to
moderate prescriptions (+/- 3.00 D).
.
Q: Is there any likelihood of Trivex pricing coming more into line with
Polycarbonate?
A: The raw materials and casting equipment used to manufacture Trivex lenses
are different from polycarbonate lenses. Trivex material is used almost exclusively
to manufacture ophthalmic lenses. Polycarbonate chemistry is used in many other
applications – such as plastic bottles, DVDs, and other injection molded products.
Therefore, polycarbonate chemistry benefits from economies of scale that Trivex
material may never achieve. That said, the price of Trivex lenses today is more
competitive with other premium materials. In fact, Trivex lenses are less expensive
than 1.67 and 1.74 lenses but offer a more complete set of benefits for patients
with low to moderate prescriptions (+/- 3.00 D).
. Q: Is Trivex material more expensive to produce than CR39?
A: Yes, Trivex material is a more expensive than CR-39 material. The raw
materials and casting equipment used to manufacture Trivex lenses are more
expensive than CR-39 lenses.
.
Q: Did your figures for conventional PAL's include non-individualised Freeform
lenses?
A: Yes, our figures classified progressive lenses surfaced using digital surfacing
equipment (freeform) where only the sphere and cylinder are applied as
“Conventional PAL”. At least one additional “individualized” measurement is
required to be classified as “Individual PAL”.
. Q: Is there a budget for manufacturers to market Trivex lenses directly to the
consumer, such as the approach taken by Transitions?
A: PPG will continue to work through our lens manufacturer, laboratory and ECP
partners to market the features and benefits of Trivex lenses to consumers. We
believe that the value of the ECP’s recommendation is ultimately greater than the
investment that we could make in an expensive consumer media buy. We are
looking to support our Trivex Lens Specialists with the recall letters they could
send to the patients, point-of-sale materials to make recommendation process
easier from the ECP to the patient and additional optician education opportunities
like our recent webinar with ABDO.
.
Q: Is there a simple non destructive test for identifying Trivex lenses when dealing
new patients wearing lenses of unknown material?
A: No, unfortunately there is not a simple, non-destructive test to identify Trivex
lenses.
.
Q: When referring to high-end entry, coatings and gadgets (upgrading mobile
phones etc.) you are considering the patients under the age of say 55 (I’m guessing
here). What with our huge over 60's population - most of whom claiming their NHS
sight test, there is an reduced inclination to invest in coatings etc. they are old
school patients who see specs as a necessity not an accessory. I do agree that we
should better promote new technology but 'selling' the extras is very tricky for a
substantial size patient sector. It would be interesting to see the age range of
patients used to collate data.
A: Yes, we agree that there is a type of patient who is not interested in a value-
added, higher performing product. We believe, however, that we should challenge
ourselves to allow the patient to make the decision with the best product offered to
them. If an optician declines to offer a value-added product to the patient, there is
no way of knowing whether or not that patient is interested. Research shows that
90% of consumers will defer to the recommendation of the eye care professional.
We should offer the best products for the patient and allow them to make the
decision.
.
Q: Does the panel feel that the seed can be sown in the test room by Optometrists
regarding new materials/coatings? The DO's can then advise more fully
A: Yes, it can be beneficial for the optometrist to discuss lens options and
recommendations with the patient in the exam room. However, a professional
optician who is knowledgeable about lens technologies and provides their expert
opinion can have as much influence on the patient’s decision. In fact, research
shows that 9 out of 10 patients will choose their eye care professional’s spectacle
lens recommendation
.
Q: Phone salespersons always give a hard sell to get consumers to upgrade. Do
you think ECP's are afraid of coming across as hard sellers and therefore alienating
our patients?
How would you handle to cost aspect of new technology, as many of the new
lenses are much more expensive?
.
A: Many patients are looking for an optician’s professional opinion. Instead of
“selling products”, opticians should consider that they are “recommending visual
solutions.” Provide the patient with the best recommendation possible supported
by a solid understanding of lens technologies and features and allow the patient to
make the decision.
.
.
Q: Are Trivex lenses available with Transitions?
A: Yes, Trivex lenses are available in the latest Transitions lens technologies,
including Transitions Signature 7, Transitions XTRActive and Transitions Vantage
lenses. In addition, Trivex lenses are also available with photochromic
technologies from other lens manufacturers.
.
Q: As technology improves will there be a Trivex 2 which for instance will be
thinner, have a higher Abbe value? but still offer its basic advantages. Is there any
prospect of higher index in urethane Trivex type materials?
A: While not a replacement for Trivex lenses, PPG developed Tribrid lenses as an
extension of its performance lens material family. Trivex lenses provide the best
performance for patients with low to moderate prescriptions. Tribrid lenses feature
a higher refractive index (1.60) and similar optical performance and lightweight
properties
.
.
Q: What is Tribrid?
A: Tribrid material extends the range of PPG’s premium, performance lens
material family. Tribrid lenses were developed using a hybrid approach merging
elements of the chemistry for Trivex lens material with traditional higher-index lens
chemistry. The result is a thinner lens that provides the patient with a superior
combination of performance benefits suited to patients with stronger prescriptions
within the range of +/-3.00 to +/-7.00 diopters. Tribrid material features optical
clarity (Abbe number 41), lightweight comfort (density 1.23 g/cm3), thinness
(refractive index 1.60), impact resistance (up to 5 times stronger than other 1.60
and 1.67 lenses) and 100% UV protection.
.
Q: Am I correct in thinking that Tribrid lenses have a RI of 1.6 and if so, how does
this differ chemically to Trivex lenses. Do they have superior optical properties
compared to their 1.6 counterparts as Trivex lenses does compared to CR39?
.
A: Yes, Tribrid lenses have a refractive index of 1.60. Chemically, Tribrid lenses
are similar to Trivex lenses; however, there are some key differences in the
chemistry that affect the overall properties of the lenses. Tribrid lenses have a 42
Abbe number; Trivex lenses have a 45 Abbe number and CR-39 lenses have a 58
Abbe number.
.
.
Q: Which lens manufacturers offer Trivex lenses in the UK?
A: Trivex lenses in the UK from the following manufacturers/laboratories:
BBGR Berkshire Caledonian Eye Index
Jai Kudo Horizon Hoya LensTec
Norville Quincey Rawdon Riviera Rimless Glazing
Rodenstock Seiko Shamir Sinclair
Tant Younger Optics Waterside WLC
.
Q: How large a base curve can Trivex lenses be made in? and will this material
eventually replace polycarbonate
A: Trivex lenses are available up to at least a +8 base curve but it always best to
check with your preferred lens supplier to get the most up to date availabilities and
offerings. As to whether or not Trivex will replace polycarbonate – I don’t think so.
I think both materials have a market segment. With polycarbonate you get an
impact resistant lens with poor optical quality and with Trivex you get not only an
impact resistant lens, you get the lightest weight lens available and much
improved optical performance over polycarbonate.
. Q: Can coatings be added to Trivex easily?
A: Yes, Trivex lenses are compatible with most coatings – including hardcoat, anti-
reflective, anti-fog, mirror, etc., coatings.
.
.
.
Q: Is Trivex purely 1.53 index?
A: Yes, Trivex lenses have a 1.53 refractive index.
.
.
.
Q: Hi, sometimes you will get the odd patient who will not settle in a high index
aspheric lens. Would they still have the same issues with Trivex lenses as the Abbe
no. is nearer basic 1.5 CR39 and the optical quality is retained.
A: Trivex material may possibly resolve the optical performance issues that some
patient experience with high index lenses, particularly if the patient is wearing 1.67
or higher index lenses. The Abbe number for 1.67 lenses is 31 while Abbe
Number of Trivex lenses is 45.
.
.
Q: Is there any provision for this webinar to be made available as a video that could
be used as info/training for other staff members? Or even the powerpoint
presentation?
.
A: The video from the webinar and the PowerPoint presentation are available at
www.trivexspecialist.co.uk.
.
Q: What happens next to get the CET points ?
.
A: The list of opticians who registered their GOC number and watched the entire
webinar has been submitted to the ABDO who will then forward the info to GOC.
Once the CET point has been uploaded, GOC will email you notification that your
CET point is uploaded.
.
.
Thank you
Dora Plisic Trade Manager PPG Optical Materials www.trivexspecialist.co.uk [email protected]
For Trivex Lens Specialist Practices, UK