It seems that free-form or digitally surfaced lenses are discussed
everywhere you look today in the trade journals. However, they
are usually describing a new enhancement to progressive lenses.
This course describes a larger opportunity for this technology
and an easy way for opticians and their labs to provide
“high-definition” lenses—lenses made using free-form technology
and resulting in better vision in single-vision designs. First, why
should we provide better vision opportunities for the single-vision
wearer? And if we do, what lenses are available that can achieve
high definition performance? To answer this we need to review
the single-vision population segment and the opportunity to
improve patient satisfaction and increase practice growth using
specially designed single-vision lenses.
THE SINGLE-VISION LENS MARKET
The average age of the U.S. population is young in comparison to
the populations of
Europe and Japan.
Moreover, it is quite
stable (Fig. 1). This
may be surprising to
many since most
population discussions in optics have
centered on aging
Baby Boomers and
the lenses that best
meet their needs for
near and intermediate tasks. What is
often forgotten is the
fact that America
has a relatively
young immigrant population made up of families and their
young children. As a result, individual and chain retail practices
have a large single-vision customer base and the market for
single-vision lenses continues to increase. In addition, a pair of
single-vision readers for the presbyope, especially seniors, is
typically recommended (Fig. 2).
Single-vision lenses represent a real opportunity for all practices
and, in fact, on average make up about half of all the patients seen
in all offices across the U.S. So it only makes sense that
providing new solutions in single vision is a better way to compete
and differentiate your business. Think about how many single
vision patients you have in your office every day, every year.
ASPHERIC AND DOUBLE ASPHERIC LENSES
The opportunities for single-vision aspheric lenses are relatively
well known. Aspheric lenses improve the cosmetics of a pair of
glasses by using surface curves that are flatter centrally and progressively flattened (in plus prescriptions) as one moves from lens
center to edge. The result is lenses that are thinner overall than the
same prescription in standard spherical lenses with steeper curves. 
This thinning and flattening
reduces the magnification of the
wearer’s eyes as seen through the
lens by others, as well as the
world the wearer sees, and when
specifically controlled ensures
peripheral vision is optimized to be equal to or better than the
peripheral vision in standard “best form” spherical design lenses.
For the wearer, this results in lenses that look better and perform
better since the world they see is closer to natural size. In addition,
the lenses provide a larger clear field-of-vision through the window of the lens frame, since magnification of objects seen through
the lens has been neutralized.
However, modern aspheric semi-finished lens blanks are
rotationally symmetrical—that is, within a base curve, there is only
one amount of asphericity and it is the same in all meridians for all
prescriptions for which the lens blank is intended. Therefore,
prescriptions with cylinder corrections (for astigmatism) have only
one meridian corrected by the asphericity. For patients with
astigmatism, the resulting areas of clear vision are improved most
significantly in the sphere power meridian of the prescription. The
cylinder meridian would not have the correct asphericity due to
the difference in power and the field of clear vision in that meridian
would be reduced when compared to the other meridian.
If the ability to aspherize the power in the cylinder meridian was
also possible, then the field of clear vision in both meridians would
be further improved and you would be able to offer the same
quality of vision to the full range of single-vision wearers, including
those with high prescriptions. This is, in fact, the case for lenses
called double aspheric.
These lenses have two different amounts of
asphericity on the same
surface, located 90 degrees
apart.
Only a few manufacturers cast finished lenses with
an atoric back surface (different asphericity in each meridian) and these have been typically
limited to 1.67 high-index lenses. Another option is to free-form
the back surface of the lens with the correct asphericity for each
power, but this approach is as yet very limited in availability.
A unique and patented solution is to use the Double Aspheric
lens from Augen Optics. It is available to your laboratory as a front
surface, double aspheric, semi-finished lens blank in Trivex and
1.56 high-index (Fig. 3). Your laboratory only needs to grind the
back surface to create the prescription in the same way it now
supplies any Rx back to you.
HOW OFTEN WOULD THE DOUBLE ASPHERIC
SOLUTION BE NEEDED?
In an analysis of prescriptions received by the laboratory, as many
as 46 percent of the cylinder prescription distribution is equal to
or more than 0.75
diopters (Fig. 4). That
suggests there is a
large opportunity in
the way one might
order aspheric lenses.
For spherical prescriptions or low cylinders, lenses would be
ordered as “aspheric.”
For cylinder prescriptions with values of 0.75 and more, a double aspheric is a better
choice for delivering clearer vision with wider fields of view to
patients with higher cylinder Rxs. With the Augen Optics
Aspheric/Double Aspheric lens series, the correct aspheric design
for the prescription is predetermined by the base curve, so you
aren’t required to make that determination when ordering the lens.
A PRACTICE-GROWING OPTION
Practice or business growth can be interpreted in a number of
ways. For example, improve wearer satisfaction by providing better
vision and business should grow. Increase the average lens selling
price while watching the cost of eyewear dispensed and profits go
right to the bottom line. If both happen, then the overall practice
or business grows and as opticians recognize their successes, they
use the lenses that support these strategies more consistently.
The single-vision market provides a unique opportunity to grow
your business with lenses that deliver increased wearer satisfaction
at a reasonable cost. The lens market is large and growing, and makes up a real part of every office’s patient base. In fact, for many
offices or chain retail locations, the customer demographics are
significant in the number of younger patients seen. Therefore, the
aspheric/double aspheric lens is an ideal product whose benefits
are worth promoting to patients.
By using aspheric and double aspheric designs as your primary
dispensed single-vision lenses, you can give your patients a
better-looking pair of glasses while delivering improved optics,
even for high prescriptions. For the patient’s budget, aspheric and
double-aspheric lenses are the logical step before free-form,
preparing the patient for the option of customized single-vision
lenses via direct surfacing as that becomes part of the regular
products available from your laboratory. Double aspherics are the
practical way to guide your customers to a better quality product
and a good option for the full range of astigmatic patients.
AUGEN CENTURION SERIES ASPHERIC/DOUBLE
ASPHERIC LENSES
In the aspherics category, Augen Optics introduces the Centurion
Series Aspheric and Double Aspheric single-vision lenses. The
lenses allow wearers to see with increased clarity in all viewing
directions. In a unique and patented design (US 7,111,937 B2), the
Centurion Series Aspheric lens is optimized for prescriptions with
no or low cylinders (0.00 to -0.50 cylinders), while the Double
Aspheric corrects both principal meridians simultaneously for
cylinders of 0.75D and above. In both cases, the molds are digitally
surfaced to produce high-definition lenses of increased precision. 
To provide patients with wider fields of natural vision and
improve the appearance of their eyewear and overall looks, switch
spherical and low cylinder prescriptions to aspheric designs, and
cylinder prescriptions of 0.75D and more to double aspheric
designs. The laboratory will choose the correct lens blank based
on the prescription—and the doctor and dispenser will deliver a
lens that better meets the wearer’s needs.
Remember, aspheric lenses use flatter base curves, allowing for
better cosmetics with thinner centers in plus prescriptions. The
asphericity is controlled to deliver the peripheral clarity the patient
enjoyed in standard form lens designs. In minus-prescription
aspheres, the periphery gets steeper for better peripheral vision
with the additional benefit of reduced edge thickness.
Here’s what it means. If a standard spherical design lens is
ordered, the lab will choose the correct lens from that design’s
base curve selection chart. For example, an Rx of R +2.50 sphere
and L +2.50 – 1.50 x 180 would normally be processed on a 6
base lens using a standard steeper best form design. The same base
curve would be used for both lenses (Fig. 5).
The spherical base curve in a traditional design delivers clear
vision for only a small portion of the prescriptions in the central
area of this portion of the chart. For the prescriptions with higher
powers and cylinders, the patient has increased blur and distortion
when the eye moves away from center. The Centurion Series is
unique because it provides two kinds of aspheric lenses to correct
this problem by gradually aspherizing the curve toward the edges
of the lens along one or two meridians. For every Rx, there is an
easy solution to deliver better-looking lenses that can also deliver
excellent vision.
In the above prescription, the Centurion lenses ordered would
use an aspheric for the right lens and double aspheric for the left,
as follows. The right lens would be delivered as an A5.00 base
aspheric lens, the left as an AA5.00 base double aspheric (Fig. 6).
In this way, each lens corrects for cosmetics and vision based on
the prescription.
With this type of solution, all prescriptions are automatically
corrected so the cylinder and sphere errors are kept to a minimum.
The design series uses asphericity in a way ensuring that out to a
30-degree rotation (about 15mm in either direction from center)
errors are limited to 0.12D (distortion and astigmatic error).
This ensures that vision remains crisp and the field is
large. It also allows dispensers to have the same expectation of
performance from prescription to prescription (Fig. 7 and 8). Also,
compare the two lens base curve selection charts. Note there are lend themselves to create astigmatic surfaces in spectacle lenses.
These “dual aspheric cylinder” surfaces create a 0.33D cylinder on
the front and provide aspheric front surface cylinder to increase
the range of Rxs with dual meridian correction. This is an opportunity for the laboratory as well as the ECP. The Centurion Series
single-vision lens designs result in less distortion and clearer vision
not only side-to-side, but top to bottom as well. In another simulation, the viewer sees the image lines straighter and undistorted.
 
THE FINANCIAL SIDE
Improving a patient’s vision and the look of their glasses benefits
the patient and can add revenue and improve practice growth. For
example, consider bundling the availability of either Trivex or 1.56
with its automatic asphericity and deliver a better product at a
higher ASP. In this way, both the office and the patients win.
In many managed vision care plans, asphericity as well as higher
index or Trivex options are a paid benefit. Use the patient’s benefit to pay for the basics and deliver a better pair of glasses they can
now afford.
AVAILABLE WHEN NEEDED
Available in plastic, Trivex, new Trivex Transitions VI, 1.56 high
index and Sunsensors +, the Augen Centurion Series ensures all
patients can get an aspheric or double aspheric lens when needed.
Having both material and design flexibility ensures that the best
vision and looks can be delivered at all times.
Also, remember all quality lens designs are further improved
with anti-reflective coating, which ensures that the vision delivered
is as crisp as intended.
CONCLUSION
The large U.S. single-vision market represents a waiting opportunity for every office. Consider the use of aspheric and double
aspheric lenses as a way to grow both patient satisfaction and your
bottom line through consistent delivery of wider, clearer vision to
single-vision wearers.
New Centurion Series Aspheric and Double Aspheric lenses
from Augen Optics provide better-looking eyewear and better
vision to the full range of single-vision patients, especially astigmatic patients with high prescriptions. |