ONE SIZE CAN'T FIT ALL

But, How Personal Can/Should You Get?

By Mark Mattison-Shupnick, ABOM

Think of three different people that are presbyopic, in three different jobs in or outside the home, which you know well. Now, think of their favorite sports and pastimes, work environment, their size (PD, height, arm length), posture and tell me about a single progressive that works perfectly for all. Tough to answer, I know, because you're saying, "…to fit someone perfectly for their sport or work as well as their size, posture, requires different lenses and frames."

For example, she plays golf and that's very different than when she's in court or doing research for her next case in her law library office…" The other two? He's a detective, lots of driving and street work but also office and reports, would love to be fishing instead; she's a freelance writer, works from home but needs those breaks and a walk for new inspiration.

Each has very varied visual demands and while so many ECPs want a one lens solution, it no longer makes professional sense to give everyone the same exact lens. Moreover, it doesn't work. The answer is to customize the eyewear for each patient, using a sensible balance of the methods of customization that you think would make a valued difference. Having a lens that provides all the forms of customization is the answer.

INTRODUCING NEW SEIKO SUPERIOR PROGRESSIVE LENSES

In this product spotlight, we'll discuss how SEIKO combines some brand new customization options, as well as the contemporary ones that you've begun to use, in a new progressive lens brand called SEIKO Superior.

Choosing the final form of the SEIKO Superior lens is a simple process of identifying overall patient needs to determine one of the three designs weighted for Near-priority,

Far-priority or Balanced vision. Then, choose the corridor length considering the patient's previous lens and the new frame and fitting height. To improve the clear field of view, Superior surfacing calculations adjust internal surface design, edge to edge, using pantoscopic lens tilt, measured from the fitted frame. Finally, reading distance can be specified so that the near inset is correct. Why would I want to specify these values and add more complications to the ordering process?

This has happened to most of us. The patient moves to a larger "B" measurement frame with a higher fitting height. The lab returns a free-form lens with a longer corridor. Why? The corridor has been adjusted automatically to use the available "B" of the frame for the fitting height ordered. This delivers a certain minimum near size vertically. The patient then reports that the reading area is now "farther down in the glasses" and noticeably different; they're not completely happy. If they don't need the somewhat wider intermediate of a longer corridor, you end up trying to adjust the frame to get the reading area subjectively higher. SEIKO Superior allows you to produce a specific reading height separate from fitting height.

Choosing the position of the reading area horizontally in the lens is actually complex. In most optimized lenses today, the inset varies by base curve (variable inset). For best results the way a patient normally holds reading material i.e., how long their arms are, their most comfortable arm position (perhaps it's affected by desk and chair height, or whether they read on a tablet, smartphone or laptop) and the distance from their eyes to the reading material itself should be considered. However, it is not common practice for opticians to specify near PD for progressives.

Ever wonder why we get patients who tell us that distance is great but reading requires a slight but different head turn to read clearly. The distance PD, near PD and the distance to the reading material affects the amount of convergence required. The prismatic effects of the distance prescription further affect the amount of convergence required as well as the dominant eye. Head position for the dominant eye will often position it to look directly at reading material while the other eye is required to turn more.

If you've had these height and reading problems, SEIKO Superior offers you a solution because you are in control of corridor length and reading inset. Specify pantoscopic tilt and the rest of the lens will be customized from edge to edge, for the prescription required. And, if you don't need to specify each parameter (the patient's fit is equivalent to the averages) or want to use the SEIKO default averages, the lab will automatically do that instead. Ordering is seamless. Nice huh, let's look at each of these new opportunities for precision fitting in more detail.

USE WEIGHTED DESIGNS

In a recent Premium Lenses Jobson MarketPulse Survey (Feb 2014) only 36% of the respondents reported using personalized progressive lenses. That means that most progressives are still 'general purpose' progressives i.e., designed for zone size and fitting values for the average patient. More of a one kind fits all approach. That makes it easy for the office to order lenses but can't really differentiate your office from others. It isn't necessarily the best lens to suggest for the patient.

Personalizing lenses can improve vision straight ahead but more importantly it improves vision over the entire lens. That's important for astigmatic and high-powered prescriptions. I also find it successful for the patient that didn't wear glasses until presbyopia and complains about the blur in their new lenses. It always gets a response from patients that they see 'better'. In fact in the survey, of those that did dispense personalized progressives, 75% reported that they were extremely or very satisfied with the results both for the patient as well as the office. That means that with the right lens choice and the flexibility to order lenses with patient differences, there are more opportunities to get it right.

Matching the patient to a weighted design lens provides a further tool to get the lenses right. For example, today's mobile lifestyle changes 'normal' reading position and posture. If one asks, "Tell me about your work, where do you do your most reading, show me how you hold the book (tablet and/or smartphone) and the first two reasons that you wear prescription glasses", it's easy to suggest a Near-priority (N), Far-priority (F) or Balanced (B) progressive lens platform. Use Near for indoor/office environments where there's a need for clear, stable, prolonged near vision. Presbyopes who use their eyewear mainly for distance/outdoor work where a clearer and wider periphery enhances the field of view (truck driver, myopes where reading is less in demand) would notice a difference with distance vision optimized. For new presbyopes and people whose demands vary widely, use a balanced design lens.

Questions for patients and observations to identify

Nothing technical here since patients want your experienced and knowledgeable recommendation. Besides asking patients how they will use their glasses, ask them what they don't like about their current eyewear. Probe their answers with more questions until you discover when they like their glasses the least. If a weighted design helps, that will be new information for patients and they'll be more satisfied with their new eyewear. When moving amongst the frame displays, watch the patient's posture as they look at frames from a distance and then close up. Now's the time to ask about which kinds of vision they spend more time at or which they find more taxing. Your successes at choosing the basic design platform increase personalized lens use because success and patient satisfaction helps make the decision which lens becomes your first choice.

EASY READING

Reading satisfaction in progressives is the result of the right Add power as well as the correct positioning of the reading zone, vertically and horizontally. Vertically, the distance from the fitting cross to reading is called corridor length. Horizontally it's called inset. How long a corridor and, what should the inset be? Depends…

Two caveats first. The reading Add should be correct for the reading distance that the patient will most often use. The doctor and the patient determine the preferred reading distance during the refraction portion of the exam. The doctor positions the reading card on the near point rod at anywhere from usually 12 to 18 inches. Obviously, reading distance varies when sitting reading a book or magazine, shopping and when multitasking, like reading a tablet while watching TV. Younger presbyopes may read higher in the corridor using their reserve of accommodation while presbyopes with +2.25 or +2.50 adds use the full Add reading position. Why then is SEIKO Superior an opportunity? Both the corridor length and inset can be specified.

Vertical Requirements

The reading zone is located using the frame's "B" size and fitting height (pupil center). Considering minimum fitting height for lenses i.e., ensuring 3 or 4mm of vertical reading availability, we choose lenses that fit frames, often without thinking about changes to corridor length as we switch patients from one size to another. Most optimized digital lenses make a variety of corridor lengths available. However, if not specified and recorded, from eyeglass to eyeglass, the corridor length supplied can vary like our larger "B" size frame example at the beginning of this paper.

SEIKO Superior provides 11 corridor lengths in increments of 1mm starting with an 8mm length and minimum fitting height of 12mm (8mm, 12mm) all the way to 18mm length and 22mm minimum fitting height. That teaches you that for reading there is a 4mm reading depth. Want more reading? Use a shorter corridor length. Want to mimic the habitual glasses (the patient's current eyewear), consider that the reading is 4mm in depth and subtract that from the habitual glasses fitting height. The result is the targeted corridor length for the new glasses being ordered. The patient didn't have enough corridor width, lengthen the corridor by 2-3mms and corridors widen.

Should you specify the corridor length? Yes, if it will make a defined difference based on the questions asked of the patient and your observations of them.

Questions for patients and observations to identify

When observing the patient when reading with their habitual glasses, do they lift their chin excessively? Do they look comfortable? Has anyone ever asked them these questions? If the answer is yes, no and no, you're doing things that no other optician has observed and it teaches whether to specify corridor length. Practice it – getting it wrong is the cost of education but patients are usually very resilient when you're really trying to solve a problem.

Ask, "If I could do something to make the reading better, what would it be…? Take control and meet the patient's expectations for reading (vertically).

Horizontal Requirements

Don't' stop at corridor length. Horizontally, the most comfortable point to place the lens' reading power is the result of a variety of factors. First, what is their distance PD and near PD, therefore the inset or convergence required? Next, what is the distance from the eye to the reading material (patient size, arm's length, arm's resting position, etc.) that would further modify convergence required? The closer it is, the more convergence or greater inset required.

Also, the distance Rx modifies convergence because of its prismatic effect. As the wearer converges i.e., myopes converge less (induced BI prism) and hyperopes more (induced BO prism). Lastly, head posture and the dominant eye affect the patients posture reading. There is a head rotation for many patients that points the dominant eye at the object and requires the other eye to rotate more. Try it. It's why some patients are happy with one lens fro reading and then describe a small amount of turn for the other that makes things clearer. Therefore, having the flexibility to adjust inset in each eye can help.

The question is, "Should you specify the inset?" Yes, when you think it will make a difference or the patient complains that reading was never completely comfortable, they are very tall or short or they have to move their head slightly right or left to read clearly with one of their eyes.

The SEIKO Superior variable inset calculation algorithm adjusts the location of the reading portion in the lens for specified reading distances of 14 to 99cm (6 to 39 inches). Otherwise, an average reading distance of 35cm is the default or about 14inches. That may be right for a variety of patients today since they are holding smartphones and tablets closer since the type font is newsprint size or smaller.

SEIKO Superior optimizes the near zone inset in 0.1 mm steps within a range of 0.0 - 5.0 mm. In addition, the left and right inset of the near zone may be set individually.

Questions for patients and observations to identify

What was the habitual horizontal reading position and satisfaction? Ask, "If you could have made it better…". Remember that the initial Add value is the result of the refraction and that needs to be for the correct reading distance i.e., where the patient will read for the majority of time, so the doctor needs to actively participate in this decision. In instances where I have had to send the patient back to the doctor for an Add power change, the reason was that the reading rod was set at a nominal 16 inches or left the same from the previous patient.

OPTIMIZED OR CUSTOMIZED CORRECTED

Optimizing (using the manufacturer's average fitting values) or customizing (using the measured pantoscopic tilt, specifying corridor length, inset and reading distance) the lens' power and peripheral design is the norm today. However many are not using these tools to the best advantage. Therefore, an understanding of the benefits can make communicating them easier for the patient to understand and therefore buy.

SEIKO calls its optimization process an advanced Multi-Polar Aspheric Compensation, to enhance the Superior lens from its other lenses. It considers a three-dimensional map of the eye and the lens, calculates values of the orientation of the eye and its varied axes of rotation and provides proper eye to lens alignment in all directions. In this way, patients can expect the following vision benefits.

	BENEFIT	SAY
Totally Clear Above 180° (Uncut Lens)	Widest Distance Field of Vision Expanded Peripheral Vision	"You'll notice that more of your right to left vision is clearer." (B) "Designed with a wider clear area for far vision, outdoors, for work or play." (F)
Control of Cylinder in All Meridians	Reduced Oblique Astigmatism	"Older lenses had more side blur caused more head movement, clearer lenses overall provide more comfortable panoramic vision. "
Reading and Distance Prescription in the as-worn position Tilt compensation	Eye Rotation & Lens Tilt Changes lens power to deliver the correct prescription over the majority of the lens Considers inset and reading distance Works for different ear/nose/frame tilts for improved performance For difficult Rx's	"For virtually all the ways that a frame fits, Superior lenses will provide your correct prescription." "A sophisticated lens for comfortable expanded peripheral vision, even in high cylinders and high-Add prescriptions."

Questions for patients and observations to identify

Teaching patients about better vision with new lenses can be difficult since they have thought all along that you've delivered the best for the money spent. However, technology drives interest and helps to validate the expense of new products.

Optimizing progressive lenses for lens tilt expands the clarity of the periphery and stabilzes the ability to deliver the best lens regardless of frame chosen. Giving priority to the size of the zones of progressives allows a direct solution to the way that your patient wants to wear their lenses. It removes a compromise and a learning to wear problem that one size fits all delivers. Ask, "If these lenses were clearer overall, especially for the kind of vision we identify as your priorities, wouldn't that be better?" Or, "Tell me what areas of the lens could be clearer that would make you more comfortable?"

NO PROBLEM PLUS

Almost all plus lenses are delivered with concave back surfaces. That was required for the more compromised designs of best form lenses. In addition, the lenses were pretty steep and thick. However, with advanced calculation software, high plus Superior lenses, especially with high Adds can now be delivered up to 25% flatter in profile, even when compared to other SEIKO internal free-form designs.

SEIKO produces Superior using flatter bases and when appropriate convex back curves. This is possible since the back lens designs are optimized to deliver thinner lenses and better peripheral optics.

ORDERING? THINK LIKE A LENS DESIGNER

Like designing lenses, placing the order is simple if you create a process.

First choose the basic design – Balance (B), Near (N) or Far (F) given your patient's priority based on observation and answers to your questions.

Next, choose corridor length. What was the previous corridor length? Think fitting height minus a 4mm reading height = corridor length. What is the new fitting height less 4mm? Are they the same, longer or shorter and what will be the patient experience? Will you be able to say that the mid-range in this new lens will be more helpful since the reading is a little further down or I know that you've loved how easy it was to access the reading, "I'll make sure that it is the same place again…" Are there any other corridor length considerations?

Then, measure lens/frame tilt. Be sure to practice measuring tilt on colleagues first. If you have a digital measuring device, use that. If not… Ask the patient to stand and turn to look at something more than 20 feet away, say out a window or across the office. Stand next to them and place your hand on their arm or shoulder, as you talk to them. This most often gets them comfortable and distracts them from trying to hold the posture they think you want. Ask them to hold that head position while you place the flat of the SEIKO tilt-measuring device against the front of the right or left top and bottom eyewire. Read and record the tilt value.

First choose the basic design – Balance (B), Near (N) or Far (F) given your patient's priority based on observation and answers to your questions.

It looks like this, pretty straight forward.

Default or Average Values?

Default means simplified. These are the average fitting values that lens designers use when calculating design surfaces of lenses. I never liked the word 'default' but it means to revert to a pre-selected number. Why should you let the lab use the average values?

First, the patient is average in the way that they wear their lenses i.e., the patient's measurements are equivalent to the manufacturers. Or, your office does not yet have the tools, training or practice to take personalized lens measurements for customized lenses.

The default values for SEIKO Superior are: Design = Balanced (B), Corridor length - match fitting height to the longest corridor that will fit, Tilt, 10 degrees, Reading distance, 35cm (about 14 inches), Inset, 2.0mm (that's the average difference of far and near corneal reflex PD's)

Obviously, your office can customize some and use the defaults for others, depends… Not every patient wants the best or can spend for it, regardless of the cost. However, getting good at personalized measurements is important for the future, yours and the office's. More lens options for better vision rely on constructing the lens based on the actual way that patients wear their lenses. As a result, good measuring skills enhance your value, improves the office efficiency as well as helps differentiate the office from others.

CONCLUSION

To fit patients perfectly for their sport or work as well as their size and posture, requires different lenses and frames. SEIKO Superior is an "ultra-personalized lens" that features 3 options for the basic design (Balanced, Near-priority and Far-priority), 11 options for the corridor length, 51 options for the near zone inset and 21 options for the frame pantoscopic tilt. It is available in a wide variety of materials and coatings with add powers from +0.50 to +4.00 (8 & 9mm corridors to +3.00). With that in mind, it's easy to understand how one size can't fit all.