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Ah, I can see it now. Virtually
all my patients wearing the best anti-reflective lenses, happier with their
vision, seeing the best that they can, driving safer at night and my business
is booming. Its all because I can deliver the best AR lenses; patients rely on
my advice and they purchase additional recommended new products. In fact, if
you want to reach me send me an email at layingaround@beachbum.com.
What, thats not the way it is?
Only about one in five actually buy AR lenses, many complain about those lenses
they had a while back that had been so hard to clean or scratched so easily or
just dont know that AR or anti-glare lenses even exist. According to a study
by Jobson Research and the Vision Council of America, when asked if consumers
would purchase lenses that were anti-glare, improved night driving, allowed
them to see and look better at a fair price, about 57 percent said yes.
However, only about 23 percent actually do. So, someone or something is getting
in the way.
Hold that Mai Taitheres some
serious work to do.
THE MARKET AROUND YOU
This is hard to understand since
most eyecare professionals and staff seem to agree that the best AR lenses
perform terrifically. They are pretty hassle free for the wearer and therefore
the ECP so its easier to add them to most patients prescriptions. So, whats
the problem?
It turns out that there are
differences in the AR products available, all dont perform exactly the same
and an understanding of those differences can help any ECP create the right
expectation for a patient. This could result in more AR used by more patients.
Also, regardless of the
technology, one has to describe AR so a patient can understand its benefits and
see its value. This has been the same for a long time but the results now best
meet the expectation. Therefore, sell AR on cosmetics, performance and vision
enhancement. Besides, it makes good business sense.
Lets review the components
needed to Live the AR Life:
1. The intent versus actual purchase disconnect.
2. Understanding patient attitudes about eyewear and product reliability while
meeting them head on with the AR challenge.
3. The technology and performance of premium AR.
4. The factors that dilute a confused market.
INTENT VS. ACTUAL DISCONNECT
Intent to buy is when a consumer
likes the attributes of a product and believes that product provides value at
its cost and purchases it. In the case of anti-reflective lenses, when
consumers are described the benefits of AR, its care and costs, about 57
percent of those intending to buy glasses in the next six months tell us they
would purchase AR.
However, of the consumers
surveyed, only about 22 to 23 percent of them had purchased AR. This suggests
that some of the 35 percent were discouraged from buying; others may have opted
for another add-on or a second pair to fit their budget and some were not
offered AR at all. The curious thing about intent numbers like these is that
just describing the benefits of AR and its effects on vision would
automatically raise usage.
Therefore, to reduce the gap talk
AR to every patient. They deserve it and they should be told to treat
themselves to better vision than delivered by an ordinary pair of non-AR
lenses. Wear AR yourself so explanations are from personal experience and
demonstrations are close at hand.
MEETING THE AR CHALLENGE
Lets face it; many of our
patients dont like buying eyeglasses for any variety of reasons. So discussing
things other than the frame and lenses may seem to them like selling extras
that are unnecessary. It couldnt be further from the truth.
First, put the objections of past
performance or any lack of it to bed. Current premium AR is made up of special
hard coats, highly compacted AR and super hydrophobics that repel dirt and
particles.
Next, decide which AR and what
performance is offered to each patient. Many offices prefer to always offer the
best AR where possible so it simplifies the choice and description used. The
newest and best AR products are clearer and stay damage free longer. Its not
that the lenses wont ever scratch but the damage is harder to cause. New AR is
easier to care for since unlike older AR, fewer particles stick and oils are
easily wiped away. As a result, lenses stay cleaner and deep scratch free
longer.
PATIENT ATTITUDE AND THE AR
CHALLENGE
All AR provides improved vision,
improved cosmetics and is patient satisfaction guaranteed but that is where the
similarities end. Today, AR is segmented in performance and pricing. The
differences in AR are related to the manufacturing process and the materials
used.
In addition, all AR provides
glare control i.e., the surface and coating reflections destructively interfere
so that the result is the elimination of the majority of surface reflections.
In this case, the glare eliminated is called distracting glare which causes eye
fatigue, reduces a wearers acuity and masks a wearers eyes by reflections.
However, the resulting stack of metal oxides that creates the anti-reflective
surface can be controlled to produce varying levels of brightness of a reflex
color and varying levels of transmission. Lenses from different manufacturers
and AR laboratories come in different reflex colors and brightness. Which is
best? Does the patient benefit from the differences? Lets investigate the
differences.
AR is currently available on the
full variety of lens materials in clear, photochromic and sun lenses. The
result is AR availability with any ophthalmic product and that makes it easy to
be able to talk AR lenses with every patient. Heres the challengerecommend AR
to all patients, regardless of the prescription, lens design, material or
treatment, occupation or use. Why? Because more reflections cause more problems
regardless of whos wearing them. And, AR lenses are better for your business.
To better talk AR, read on.
THE BEST IN AR STARTS WITH THE
BEST LENS PREPARATION
Understanding the differences in
AR coating and hard coating (HC) is one of the most important aspects of
quality coated products. Each manufacturer has a proprietary AR stack formula
based on the hard coat and substrate chemistry. Formulas can vary by material,
layer thickness, application time and reflective hue color.
In the past, AR coaters simply
used one AR coating process for all lenses, regardless of substrate, hard coat
or lack of hard coat. Todays AR coaters know the importance of a hard, solid
substrate (hard coat), on both sides of the lenses as the base for AR coatings.
A high-quality hard coat is essential to maximizing the durability of the
lenses against scratching.
Hydrophobic topcoats were first
introduced in the early 90s to help seal the AR coating and to provide for a
slicker, lower friction coating that repels water. Now, oleophobic topcoats
have been introduced that further increase the slickness, scratch resistance
and cleanability of AR products.
THE AR AND HARD COATING
RELATIONSHIP
Hard coats are tintable or
non-tintable and thermally or UV cured. Each of these types of hard coat can be
applied using a dip or a spin method.
Since the AR will only be as hard
as the substrate under it, it is imperative that the layers under the AR be
controlled. Tintable hard coats are generally softer and more porous than
non-tintable hard coats. While tintable coatings make it easier to apply a
sunshade tint, the soft surface is not optimum for an AR coating. On the other
hand, most non-tintable hard coats offer a hard stable surface that is an
excellent substrate for the application of an AR coating, but can not be
tinted.
Thermally cured hard coats are
cured in high temperature ovens over a period of several hours. UV-cured are
cured with a UV light for several seconds to a few minutes, depending on
application. Generally, it is agreed that a thermally cured hard coat has a
higher Bayer rating (hardness and abrasion resistance). While some UV cured
coatings are beginning to approximate these higher Bayer results, thermally
cured coatings are still considered the best.
Dip hard coats are applied to
both sides of the lenses during a controlled dip process. Dip hard coats offer
advantages to spin in that they cover the front and back surfaces and can be
applied to any lens style including flat top segments.
Spin hard coats, on the other
hand, are typically applied only to the back surface. This can be a problem as
the front side could be a factory applied thermal coating and the back side is
UV cured. Patients may experience significant scratching on the back of the
lens and very few on the front.
Say this to all patients:
Your glasses look great when
the lenses have no reflections and you look even better.
Vision is improved when reflections and glare is eliminated. AR lenses do
just that in everyday situations, in front of the computer and especially at
night.
Clearer lenses help improve communication.
For teens, AR helps make glasses disappear.
For adults, AR makes you see and look better.
For the senior, AR is critical for the best vision all day, everyday.
Use these words when needed:
Treat yourself.
I know that you dont want to spend for this lens thats anti-reflective but
it is important for your vision especially at night. Take care of your senior
patients with the clearest lenses possible. A 65 year old needs nearly six
times the amount of visible light than an 18 year old.
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While hard coats can be applied
in a number of environments through a large range of equipment, best results
are achieved when the application is stringently controlled by using a dip
coating applied equally to the front and back sides.
PREMIUM PRIMERS
While not included in all hard
coating processes, a primer layer can offer real advantages to the adhesion
properties and impact resistance of AR lenses. First, this layer is very sticky
and can be attached to virtually any lens substrate. It is just as sticky to
the next layer hard coat and one can use the hardest, most scratch-resistant
hard coat since it sticks to the primer.
A proper primer layer can add
significant shock resistance especially to thin center lenses. This allows for
a more consistent, controlled hard coat and AR stack application. Using a
premium primer layer as the first step in the HC process, AR coaters more
closely control the overall quality and durability of the end product.
LENS QUALITY
Lab in-line quality control
checks throughout the surface process, ensures the highest possible surface
quality.
Residue from wax blocking can
cause contamination of cleaning and hard coating equipment and eventually cause
adhesion failures to the coating layers. AR coaters must use special cleaning
processes to ensure all wax particles are completely removed before AR coating.
The lab should use surface saver tape for lens protection and reduced
contamination. It is best recommended to ultra clean the lens after surfacing.
Any defect that is on the lens
prior to AR and hard coat application will generally be more apparent and
pronounced once the AR is applied. Scratches or defects that seem minute prior
to AR coating will be more pronounced after AR due to the reduced surface
reflections. It should also be pointed out that due to differences in
application techniques and coating flow variations, dip hard coats may not fill
in scratches or voids as readily as in-house lab spin hard coats.
AR COATING TECHNOLOGY
Single-vision stock AR lenses are
produced en mass by lens manufacturers and AR coating service centers and sold
as finished AR lenses. All other lenses i.e., multifocals and surfaced
single-vision lenses are custom coated. For example, iCoat Company and Opticote
are custom and regional coating labs while Custom Eyes, SOLA Technologies,
Expert or VSP are examples of in-lab AR. In each of these facilities a variety
of AR can be produced.
Front, back or both surfaces? For AR lenses to work best, AR is
required on both lens surfaces. Front and back surface reflections are additive
and get worse as the index increases. In fact with almost half the lenses today
at higher indices, the need for AR is more important. On sun lenses the
requirement is even more extreme since a dark tinted or polarized lens acts
like a mirror and reflects light and images on the lens back surface. In
addition, the concave shape of the back lens surface magnifies images (think of
a make-up mirror) so sun lenses can create a back reflection that is large and
block high-performance vision when it is needed.
Photochromics Photochromics are activated by UV therefore, any AR
applied should not absorb any UV radiation. As a result, AR laboratories work
closely with the photochromic lens manufacturers to ensure a UV pass AR. If
the AR affects the performance of the photochromic, talk to your lab.
AR Durability As
stated earlier, the durability of an AR lens is primarily a function of the
durability of the surface on which it is applied. Therefore, the more durable
the hard coat or the substrate, the more durable the AR lens. So, glass AR
lenses have the best surface durability but not necessarily the best impact
resistance. With that as a measure, we can then see that AR applied directly on
a lens surface without hard coat makes the durability only as good as the lens
material itself.
| Material |
Index
|
Percent
Reflection
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| Plastic |
1.50
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~8.0%
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Polycarbonate
or High-Index |
1.59
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~11.0%
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| High-Index |
1.67
|
~12.5%
|
| Utra-High-Index |
1.74
|
~14.5%
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| Dark Sun Lenses |
any
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Highly
reflective
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Therefore,
materials very sensitive to abrasion and scratches need excellent hard coats
for excellent AR performance. It is in this that AR lens durability varies from
supplier to supplier. Suppliers should be able describe the effectiveness of
durability test results. Other technologies improve durability by compacting
the AR molecules and layers. For best results, start with uncoated lenses and
apply hard coats to both surfaces simultaneously. Too hard a surface may
compromise impact resistance.
HOW MANY LAYERS OF AR?
The number of AR layers is
determined by the manufacturer but more does-nt necessarily mean better. There
are always an uneven number of layers i.e., three, five or seven typically in
spectacle lens coatings. Denser designs improve scratch resistance and the
layers are tuned for better temperature change resistance. The top most layer
in premium AR is an oleophobic topcoat.
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higher the value the more abrasion resistant the AR lens. Bayer testing abrades
an uncoated plastic lens standard and measures haze gain after oscillating in a
sand bath. The resulting number is the ratio of how many times better the AR
lens is in resisting abrasion (haze). For example, lens F is 7.6 times more
abrasion resistant than the uncoated plastic test standard and more abrasion
resistant than four of the other lenses tested. |
EASE OF CLEANING
Newer premium AR lenses are easy
to clean. Gone are the comments: I cant keep my lenses clean. This new
cleanability is what makes new premium AR easier to sell. An oleophobic
property causes oils and liquids to bead into tighter balls making it easy to
wipe them away. In addition, the best topcoats will no longer trap those oils
and smear when wiping.
For dust and airborne particles,
the denser packed surface provides an anti-static property that doesnt attract
dust and dirt. With fewer particles attracted to the lens surface, lenses
scratch less and stay cleaner longer.
REFLEX COLOR IM GLAD ITS THERE
High transmission is a function
of low surface reflectance. However, AR coatings have colors and this is a
result of higher reflectance of specific color wavelengths. Is one color better
than another? Not necessarily, however some patients do not like bright reflex
colors. As a result, the muted yellow/green, green or blue/green colors are
more preferred.
Should coatings be colorless?
Most of the sophisticated improvements like design or UV absorption we sell are
invisible. Often, I can imagine the patient wondering if they received what
they paid for. This is not the case with AR lenses. The reflection color tells
them they received what they paid for. Dont hesitate to point it out.
NOT TOO CRAZY ABOUT CRAZING
Thin centered lenses can crackle
the coating when compressed or bent. This is called crazing and shows up after
edging or when patients have exposed their glasses to temperature extremes.
That also means lenses can be crazed in the salt pan, hot air blower or the
dashboard of a car.
Crazing is often not seen easily
but should be suspect when the patient returns saying they cannot get their
lenses clean anymore or all of a sudden, the lenses are not as clear. The
all of a sudden is your clue. To see a crazed lens hold the lens below a bright
spotlight and the crazing will light up. Dont look through itlook at it.
PROPER CARE
While todays premium AR lenses
are much more durable than standard AR of the past, products still need proper
care to ensure their longevity. AR coated lenses should be cleaned on a regular
basis, whenever possible cleaned wet and stored in a case. AR lenses should
never be left on the dashboard of a car, near other heat sources or exposed to
harsh chemicals. Care should also be taken in the lab or dispensary when
adjusting frames with AR lenses in them as the heat from a salt pan or hot air
blower can cause crazing and cracking.
In summary, have total confidence
in the premium AR lenses currently available. By taking the time to research
their choices, eyecare practitioners can offer AR to each and every patient and
have the confidence that the product will last. The developments and technology
advancements in equipment, processes and chemistry help immensely in promoting
AR as an obvious choice for each and every patients pair of eyewear.
Tips on Edging AR
Lenses
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(source:
AR Council)
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Cut the lens down
slowly in several steps.
Use a plastic film tape or surface-saver tape between the leap pad and both
front and back lens surfaces.
Try a plastic block on the front side.
De-block the lens immediately after edging.
When de blocking, put it into warm, soapy water to ensure the
block comes off easily. Pulling the block off dry can cause stress
cracks in the coating.
Equalize the chuck pressure on both sides of the lens to eliminate lens
flexing and make sure the block and the diameter of the clamp are the same
size.
Minimize operator handling of the lens to reduce the opportunity of scratches
occurring.
Maintain a meticulously clean lab environment, as any foreign particle on
hands, in the job tray or in the work area could cause scratches.
If not comfortable edging AR
lenses yourself, the entire job can be sent to your lab for processing.
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