1. The “Ideal Progressive”
Progressive Lenses
Viewing Areas
The “Ideal Progressive”
Distance zone
Intermediate zone
In our example here we are looking at the ideal sphere with a 1.50 add in a progressive lens design. You have seen these graphs before and although they are certainly not the only criteria to aid us in selecting the right lens for the patient, they do help us understand enough about the design to aid in determining the characteristics of a lens. With this information we have an idea of what we might expect in patient reaction. Certainly even in the best design there will still be power changes – those are the blue areas – however, the goal with any design is to optimize placement of those power changes and how they ultimately affect patient visual acuity and comfort. NEXT SLIDE
Near zone

2. Progressive Lenses Influence of changed Rx Power Optimum Design with
-2.00 Cylinder
Look at what happens to the“Ideal Progressive“ once we modify the power. In this case, adding a cylinder. You can clearly see that all three primary zones (distance, intermediate and near) experience enough changes to adversely alter the lens and thus hinder potential success. I would draw your attention in particular to the distance viewing area. The encroachment of power changes above the fitting cross typically result in what we have called the“swim effect“ the patient experiences as they move their head from side to side. NEXT SLIDE

3. Progressive Lenses Influence of changed Back Vertex Distance
Optimum Design with
Back Vertex Distance of 14mm
Optimum Design with
Back Vertex Distance of 9mm
14 mm
If we discount the cylinder power and just alter the Back Vertex Distance of a Sphere we again see adverse changes to the optical characteristics of the lens. See for example the narrowing of the intermediate and near vision zones. Remember our averages? In this example we are deviating 5mm from the average off of which the optimum design was created. That 5mm at the fitting of the lens could only be compounded with slippage, a change in nose pad adjustment, etc. NEXT SLIDE

4. Progressive Lenses Influence of changed Pantoscopic Angle
Optimum Design with Pantoscopic Angle of 9°
Optimum Design with Pantoscopic Angle of 3°
The same holds true if we only alter the pantoscopic angle. Here we introduce 6 degrees of difference in angle and we experience changes in every viewing area. NEXT SLIDE

5. Progressive Lenses Influence of PD, BVD, PA, NWD and Cylinder Power
PD: mm
BVD: mm
PA: 9°
NWD: 380 mm
+5.00 Sph
PD: mm
BVD: mm
PA: 3°
NWD: 300 mm
+5.00 Sph Cyl
HIGH IMPACT SLIDE Look what happens when all three fitting changes are made to our “Ideal Progressive” and we add cylinder power. Knowing that the more colored areas there are in this graph indicate a drop in visual acuity, you don’t need a degree in lens design to see that this is a distinct departure from the result we really want to achieve. Look at how much the variable inset alone is thrown off the desired path. That alone is reason enough to look for a better approach. The crazy thing about this dramatic graph is that we know that progressive addition lenses work! Imagine how much better they would perform if these issues could be addressed.
NEXT SLIDE
Optimum Vision Reduced Visual Acuity

6. Progressive Lenses Influence of PD, BVD, PA and NWD
FACT:
Any deviation from the optimum
vertex distance
pantoscopic angle
near working distance
or base curve
on which the fundamental progressive design was
formulated, will result in a loss in patient visual acuity.
KEY POINT – HIGH IMPACT As this statement of fact demonstrates, each and every lens designer has had to work within the average parameters however, all the while knowing that a departure from the optimum measurements for any given design and base curve will result in a loss of visual acuity for the patient. This is extremely important. Imagine that this lens may actually “check out” perfectly in a lensometer however, to the patient something may “just not feel right” – enter the “non-adapt” or the always vague “I just don’t see well” patient. NEXT SLIDE

7. Progressive Lenses Influence of PD, BVD, PA and NWD
What do we do about the “Law of Averages”???
Is there an ideal progressive???
So what can we do about the law of averages and does an ideal progressive exist? If so, it would seem that based on the information we have reviewed to this point, it would have to be designed with consideration of individual patient criteria that up to this point in the history of progressives has not been considered. NEXT SLIDE

8. It is as Individual as its wearer!
Progressive Lenses
Tailor-made Lenses according to Patient’s Individual Specs
The ideal progressive lens has one distinct feature:
It is as Individual as its wearer!
Now let me introduce you to Gradal Individual and Gradal Short i. Lenses that are truly designed to meet the needs of each and every individual patient. NEXT SLIDE
Gradalâ Individual and Gradalâ Short i

9. Gradalâ Short i Gradalâ Individual
“Individualized” progressive lens surface
= Optimized lenses for every prescription
“Individualized” parameters calculated into lens design
= The “Ideal“ Progressive Addition Lens
With a lens surface that is optimized for each and every prescription possibility and with the incorporation of specific measurements unique to each wearer, Gradal Individual can truly be considered the “Ideal” progressive addition lens. NEXT SLIDE

10. Individual Progressive Lens Technology
Gradal® Individual
Gradal® Individual and Gradal® Short i
Regular PAL’s
With Gradal Individual there is no “average” base curve to fit a range of powers but rather an “individual” base curve created for each and every Rx possibility. There is no longer a need to even consider “matching base curves” as this process ensures that no matter what the prescription is, the optimum base curve will be created “individually”.
With a lens surface that is optimized for each and every prescription possibility and with the incorporation of specific measurements unique to each wearer, Gradal Individual can truly be considered the “Ideal” progressive addition lens.
NEXT SLIDE
Optimum Vision Reduced Visual Acuity

11. Progressive Lenses
Design Requirements for Optimized Rx
Incorporation of individual patient data in Rx calculation
Back Vertex Distance (BVD)
Pantoscopic Angle (PA)
Both Gradal Individual and Gradal Individual Short i are custom-manufactured for the patient using calculations for that particular patient’s back vertex distance and pantoscopic angle. We saw earlier that deviations from the average result in a less than desirable result. With Gradal Individual, it is no longer necessary to rely on the averages. NEXT SLIDE

12. Progressive Lenses
Design Requirements for Optimized Rx
Incorporation of individual patient data in Rx calculation
Pupillary Distance (PD)
Near Working Distance (NWD)
PDR
PDL
NWD:
Usually between
250 – 450 mm
The same holds true with pupillary distance and near working distance. NEXT SLIDE