Still a New and Growing Lens Category
By Mark Mattison-Shupnick, ABOM
Release Date: March 1, 2014
Expiration Date: April 1, 2015
To update the ECP on changes and adoption practices for a lens material that is capable of being the overall lens platform including:
- Why lens material is the foundation on which all lens attributes are formed.
- A material category's attributes and adoption a decade after initial introduction in a market that is slow to change.
- Learn the broader everyday uses of Trivex material.
Mark Mattison-Shupnick, ABOM, is currently director of education for Jobson Medical Information LLC, has more than 40 years of experience as an optician, was senior staff member of SOLA International and is a frequent lecturer and trainer.
This course is approved for one (1) hour of CE credit by the American Board of Opticianry (ABO). Course STWJH036-2
This course is supported by an educational grant from PPG INDUSTRIES, INC.
Trivex material's development has been
consistent with the way new technologies
build sophistication into products. In the
past, a lens material had to be more closely
matched with the prescription and the end results
wanted. This is no longer the case. By bundling
benefits through advanced lens material technology, a new lens category has taken shape and continues to grow. The growth of the Trivex material
category has coincided during a shift in consumer
purchase preferences and behaviors. In a 2012
online survey of eyeglass wearers (Fig. 1) conducted by Lightspeed Research, more than 38
percent of respondents said that "a combination
of lens attributes" was how they decided on lens
material during the purchase. That's not surprising since one of the results of the 2008 to 2009
recession made value the most important deciding
factor in a customer's purchase. When combined
with an ECP's recommendation, that accounts for
60 percent of the decision. Therefore, understanding what makes Trivex material a highly
valued, sophisticated bundle of benefits and how
you can incorporate it into your lens recommendations will provide your patients with more
value and greater satisfaction.
The lens material and its characteristics become
the foundation on which all lenses and their final
properties are built. A material's attributes form
the final product that is delivered to the patient.
However, no lens is the result of only one of its
properties (index or impact or specific gravity,
etc.). In fact, choosing a lens material because of
one attribute, such as index, can often create a
lens that isn't what the optician or the patient
expected. Lens attributes work in combination.
Consumers do have preferences, and from
VisionWatch, The Vision Council collects more
than 100,000 eyewear consumer opinions annually. For the 12 months ending September 2013,
lightness (comfort) and scratch resistance (value
and durability) combined were the most important of attributes reported by more than 60 percent
of those surveyed. In fact, lightness or comfort
becomes a much larger concern for those over 55
when eyewear is required and worn more continually. Therefore, the interaction of a lens material's
properties make the final lens. They are more
important that any one attribute.
A lens' final thinness, most important to an
additional 12 percent of respondents, is determined not only by index, but more importantly, by the material's impact resistance (for the
frame style, size and shape chosen by the
patient). The extreme impact strength of
Trivex material significantly exceeds FDA
impact requirements. This allows minus lenses
with thinner centers to be sold. Unlike lenses
made with CR-39 monomer (from PPG
Industries), which are produced to 2.0 mm
centers, lenses made with Trivex material are
produced to about 1.2 mm centers. This 0.8
mm reduction in thickness is possible in all
but the powers near plano. In addition, that
also means an equal reduction in edge thickness of almost a millimeter. When combined
with the index of 1.53, lenses are thinner yet.
In plus lenses, edges can be made thinner,
since the material is not prone to flaking or
chipping (due to tensile strength, notch sensitivity) especially when grooved.
This benefit of lens thinness is typically combined with lightness in the sales process. That's
because thinness reduces lens volume and creates the final weight of the lens. However, the
real lens weight is a function of volume and the
material's specific gravity. In this case, Trivex
material was engineered to be the lightest material (1.11g/cm3). In the same Rxs, lenses with
Trivex material are always thinner and lighter
than CR-39 monomer due to its index, extreme
impact resistance and specific gravity.
Patient Benefit—Thin and Light: When
compared to CR-39 monomer, lenses made
with Trivex material are up to 15 to 20 percent
thinner and always about a third lighter. An
aspheric design will further reduce thickness
and weight. While there are other higher index
materials that can make lenses even thinner,
lightness depends on final lens volume and its
specific gravity. Some high-index materials have
much higher specific gravities so the weight
savings when compared to Trivex material is
less than you might think. While the highest
index lens of equal power is another 15 to 20
percent thinner, within the core range, lenses
made with Trivex material are still 10 percent
lighter. For the core range of lens prescriptions
(-3.00 to +3.00), having a lighter lens is always a
selling benefit. VisionWatch patient surveys
always report that patients value the lightness
of their eyewear.
Patient Benefit—Clear Vision: Material
choice also affects the clarity of vision. A lens'
clarity is a product of Abbe, glare-free (antireflective) coating and the type of lens design
used. Prism, off-center in prescription lenses,
creates power errors and blur, the result of
chromatic aberration and the lens design. Manufacturers work hard to create lens designs that
reduce off-center power errors but the material
still contributes clarity based on its Abbe. The
higher the Abbe, the less chromatic blur. The
result is a larger, clearer field-of-view (for the
same prescription, material-to-material).
CR-39 material and glass lenses have the best
Abbe. To support a choice of Trivex material as
a replacement for CR-39 material, lens clarity
should be equivalent. After all, crisp vision is an
expectation of your patients, not something
that you sell as an added benefit.
Abbe values are a relative measure of clarity
and are not linear. Trivex material has an Abbe
value of 45, which produces lens clarity virtually
equivalent to CR-39 material.
Patient Benefit—UV Protection: UV radiation is a recognized contributor to the formation of cataracts, as well as pinqueculae, pterygia, keratitus, wrinkles and skin cancers. As
a result, lenses sold in eyewear should always
provide 100 percent UV protection. Any
choice for an everyday lens material must provide 100 percent UV protection. CR-39 monomer, depending on specific lens manufacturer
processes, absorbs between 85 to 90 percent of
UV radiation while Trivex material absorbs 100
percent. While a UV dye can be applied to
CR-39 material for added absorption, this dye
can compromise the long-term adhesion of
anti-reflective coatings and result in delamination. Therefore, it is more practical to choose a
material that provides 100 percent UV protection without additional processing. Every lens
made with Trivex material automatically
provides protection from the effects of UVA
and UVB radiation.
Patient Benefit—Impact Protection: According to The Bureau of Labor Statistics
(BLS), almost 70 percent of the eye injuries
studied occurred from falling or flying objects,
or sparks striking the eye. The best way to
prevent eye injuries is to always wear the
appropriate eye protection. Since no one can
predict when they will need eye protection, it
makes sense to have eyewear, even everyday
glasses that provide impact resistance at all
times. While it may be easier to bring up the
subject of impact resistance when talking
about kids' eyewear or sport- specific eyewear,
the truth is that everyone needs to protect
their eyes and their vision, all the time.
patients with an
everyday lens that
impact resistance, you are making
sure that their
eyes receive the
no matter the activity. Providing this protection
is even more important today, when patients
are less likely to purchase more than one pair of
glasses due to financial reasons. This means
they are more likely to wear their everyday
glasses while playing sports, working in the
yard or around the house. Lenses made with
Trivex material have 62 times the impact
resistance of ordinary plastic lenses.
One office uses this statement to get across
the message of eye protection for everyday
lenses: "Our office recommends Trivex material as our standard lens material of choice
because it provides the visual armor to protect
your eyes from both UV light, while providing
the ultimate in impact resistance, no matter
what you are doing." You are the reason that
customers purchase since almost a third of
VisionWatch survey respondents report that
the most important reason for their purchase was that it was ECP-recommended (Fig. 2).
You are a trusted eyecare advisor; use your
power to deliver the best bundle of benefits.
Frame choice also drives material choice.
Usually the patient will select their frames first
and then the lenses. This can present a problem
with some lens materials. Consider the combination of a plus lens and a grooved semi-rimless frame. Lenses made from CR-39 material
flake or chip at the thinnest corner. Oftentimes,
patients will return a pair of rimless glasses
because of star cracks around the drilled holes
or flaking at the edges.
Patient Benefit—Frame Choice Freedom: Lenses that retain their looks and safety
regardless of frame style allow patients to
select the frame of their choice knowing that
the lenses will not be affected. By selecting a
lens material that doesn't flake or crack, opticians can feel confident that no matter the
frame choice of the patient, the lenses will be
suitable for the frame.
Trivex material is unique in that it has
extremely high strength and virtually no notch
sensitivity. This means that the lenses won't
develop edge flakes or chips, and when used
for drilled rimless, won't star crack. This is particularly important in drilled polarized lenses.
Polarization efficiency is affected by compression at the drill points. Choosing Trivex material solves many problems before they start by
reducing breakage and remakes.
Eighty-five percent of the U.S. population that
requires vision correction is within the range of -3
to +3 diopters (Fig. 3), which means the majority
of patients might not require a high-index material to achieve a thin lens. Trivex material will produce an equivalent or comparably thin lens for
these prescriptions while also providing the
patient with a more robust combination of lens
attributes – optical clarity, lightweight comfort,
impact resistance and UV protection.
WHAT TO SAY
When making a lens recommendation, include
the patient benefits of the lens along with the
lens attributes. The more "true-to-life" the
description, the more it will resonate with
the patient. Again from VisionWatch, you
are in control of the lens' attributes because
consumers report that their decisions are
ECP-driven. Almost a third report that their
most important reason for purchasing is
their ECP's recommendation.
Suggesting a change to Trivex material as
a replacement for CR-39 material might
sound like this:
- I'm recommending lenses made from Trivex
material because it delivers crisp, clear vision
with exceptional optical performance.
- Your lenses will be ultra-lightweight, provid ing added comfort since Trivex material is
one of the lightest lens materials available.
- This material automatically provides 100
percent UV protection and is unsurpassed in
impact resistance and durability, meaning
your eyes will always be protected.
PREMIUM OR EVERYDAY?
Should Trivex material be considered as a premium or everyday lens material? Perhaps this is
the wrong question to ask. The correct question should be, "What is the best material for the patient's Rx and vision requirements?"
Remember, the Rx is the driver with the balance of lens properties completing the requirements. If a patient with a -2.00D Rx requires
lightweight lenses and protection in a rimless
frame, Trivex material may be the best solution
especially if the patient had a bad experience
with star cracks in a previous pair of rimless
glasses. If the Rx is -6.00D and thinness is the
number-one consideration, then a higher index
material is probably the better choice for this
Deliver the best eyewear for the patient,
which includes being selective when it comes
to recommending the lens material.
TRIVEX MATERIAL FOR KIDS
Kids need sharp, precise vision for all they do. Their active and
unpredictable lives also demand eyewear that provides the best
strength and protection.
It's estimated that 80 percent of what children learn in their
first 12 years comes through their eyes. However, children's
eyes are underdeveloped. In fact, the crystalline lens of a child's
eye is virtually transparent and offers very little protection for
the retina. The eyes of a child under the age of 10, transmit over
75 percent of UV radiation compared with 10 percent in adults,
ages 25 years and older.
Here are two scripts you can use to highlight the importance
of quality lenses for kids:
"We only use lenses made with Trivex material that provide extreme protection from UV radiation
and are impact resistant while delivering the best in clear vision for your child."
Or consider adding glare-free lenses and say, "Because children rely on their vision for learning, it is
important that they have the most durable, non-glare lenses made with Trivex material. Non-glare
lenses can eliminate headaches and tired eyes caused from white boards, computers and classroom
lighting. In addition, since children spend more time outdoors, they are exposed to more glare and
harmful UV rays. I recommend lenses that absorb 100 percent of the harmful UV rays. They are also
available in photochromic lenses that change tint when your child goes outdoors and then changes
back to clear when they come back inside."
TRIVEX MATERIAL FOR SUNWEAR?
IT'S THE RIGHT CHOICE
"High velocity impact resistance" (Z87.1 that
is) says it all. A lens material that can meet
Z87.1 high velocity impact standards ensures
that eye injuries are lessened, and your patient's
vision will be protected. The wrap shape of
many of today's sport sunwear also helps to
reduce dust, dirt and wind from getting to the
eyes. The steepness of the 8-base lens shape
adds to the impact resistance structurally, while
a polarized lens eliminates blinding glare. Since
sunwear is worn outdoors during activities
such as cycling, skiing, jogging, fishing and
golf, the likelihood of eye injury increases with
these types of activities. Providing your patients
with sunwear made with an extremely impact
resistant and UV-absorbing material like Trivex
material in polarized and/or photochromic
versions will provide the optimum protection
for their eyes.
TRICKS OF THE TRADE
When converting from a well-known material
like CR-39 material to Trivex material, there are
a few tricks-of-the-trade that savvy labs and
opticians have adopted to make their lives
easier and the results predictable.
• Let the lab choose the correct base curve, especially when lenses are digital or aspheric in
design. This is extremely important since good
peripheral vision through lenses is index, base
curve, Abbe and position of wear dependent.
Manufacturers have calculated the correct
base curve to choose to provide best vision,
and labs store those tables for lens choice when
completing an Rx order. This is still true for
digital lenses and the preferences of digital
• For the office that does its own edging: It is
easy today to edge Trivex material since edger
manufacturers have modified their systems to
add Trivex material capability. Direct drive
motors get instructions on speed and torque
from a sophisticated internal software module
by simply choosing the Trivex material mode.
The drain that carries away waste material
(swarf) has been increased in size so any heatinduced material "clumping" washes down the
drain without a clog. Water, as coolant, also
washes/cools the back of the grinding chamber
so there is little effect from any heat generated.
• For drilled rimless: Trivex material is the least
affected by drilling, so it reduces or eliminates
the possibility of star cracks or breakage. That
same tensile strength and lack of notch sensitivity allows thinner edges on grooved semi-rimless
since the groove wall is unlikely to chip or flake.
In both frames styles, it reduces the number of
remakes and improves patient satisfaction.
Making a global change to a material that can
be used every day requires good availability in
the styles and designs you dispensed.
With the advantages of free-form manufacturing in the laboratory, virtually any of the newer
optimized and/or personalized progressives and
single vision lenses can be created in Trivex
material. The latest generation photochromics
(Transitions Signature VII lenses), polarized
lenses (such as NuPolar Trilogy and NXT lenses) and blue-light blocking treatments (such as
HOYA Recharge) are now available in Trivex
material. Add the high quality scratch resistant
and AR technologies that are widely available
from multiple manufacturers, distributors and
laboratories, and the opportunity for a new lens
platform takes shape. Even frame manufacturers
are beginning to experiment with the Trivex
material platform as a lightweight, durable and
unique frame material. Companies such as
Monoqool and the Serengeti Genus collection
You'll find that Trivex material lenses are
available in the latest designs and formats
from: Augen, Essilor, HOYA, Kodak/Signet
Armorlite, Nassau, NuPolar, NXT/Intercast,
Seiko, Shamir, Shore, Transitions, Unity/VSP,
X-Cel, Younger, Zeiss and others.
As with any lens material, you'll find that there
are best uses for Trivex material while other
situations may call for a different material for
a particular patient's needs. Your optical laboratory is a great resource for lens information
Visit www.ppgtrivex.com for Trivex material
availability from the manufacturers mentioned
above. The Trivex material website has tips for
processing as well as a complete e-learning
module at www.ppgtrivex.com/education.
Review other CE courses at 2020mag.com/CE
for additional information about material
choices and visit the Opticians Handbook
(www.opticianshandbook.com) for up-to-date
information about your best material choices.
Since the material is the foundation on which
lens styles and designs are built, it's important
to start with the best combination of lens
material attributes to provide the most benefits
for each patient.
By considering the interaction of lens attributes and material properties, opticians can
offer a better choice for everyday eyewear for
their patients. Consider replacing CR-39
monomer as the standard lens material with
Trivex material and provide increased patient
**Both CR-39 monomer and Trivex material are
manufactured by PPG Industries.