Troubleshooting Progressives

We've been fitting progressive lenses for over 50 years. You’d think we’d have figured out the non-adapt problem by now. But in many ways, it’s bigger than ever.

In this guide, we’ll break down the most common (and overlooked) issues opticians face when fitting and troubleshooting progressive lenses - and how today’s advanced technologies are reshaping the conversation.

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Today’s Progressive Lenses Are Smarter - But Also More Complex

Progressive lens technology has come a long way since the 60s, 70s and 80s. The math behind modern designs is incredibly precise. But that complexity comes at a cost: You don’t always know what’s happening behind the scenes.

Then vs. Now:

  • Old progressives: One fixed design, molded into every lens.
  • Modern progressives: Custom-calculated per prescription, frame shape, position of wear and more.

Even with the same lens brand and design name, you could get drastically different lenses depending on the data you submit.

Can You Trust the Design Software?

Lens companies let you input parameters into what’s essentially a black box. It spits out a lens design, but you don’t really get to see the logic.

It’s a little like asking a politician if they care about you - they’ll tell you exactly what you want to hear.

If you enter estimated or default values - like frame box dimensions instead of an actual trace - you’ll likely get a misaligned design.

Bottom line:
Garbage in, garbage out. The data you submit has everything to do with how the final lens turns out.

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Why You Need the Frame Trace - Not Just Box Measurements

Let’s say you’re working with a large, curved frame like an aviator. If the patient’s PD is narrow, the reading area could fall way off center.

If you use box measurements, the software assumes a rectangle. It may place the reading area where there’s no lens at all after edging.

But with a frame trace, the software customizes the design to the real shape. That means:

  • Proper placement of the reading zone
  • Better patient comfort
  • Fewer remakes

Corridor Length vs. Fitting Height

In traditional lenses, the minimum fitting height dictated which lens design to use. But with freeform technology, the software now adapts corridor length based on:

  • Fitting height
  • Frame trace
  • Design choice

So if you submit a 28mm fitting height, the software might return a 14mm corridor. That’s not a mistake - that’s how variable corridor lengths work today.

What About Big Frames?

In oversized frames, the fitting height can be huge, but that doesn't mean the wearer can actually use the full range.

If the corridor extends too far down:

  • The lens might sit on the cheek
  • The patient can't reach the full reading zone
  • You could end up with complaints of discomfort or awkward posture

This is where vertex distance and pantoscopic tilt come into play. Proper alignment ensures the patient doesn’t need to crane their neck or fight their own glasses to read.

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The Role of Vertex Distance in Corridor Performance

The closer the lens is to the eye, the wider the usable corridor appears. If you tilt the lens forward (increase pantoscopic tilt), the field of view widens but the required angle of gaze increases

This can help if a patient feels the corridor is too narrow or hard to reach. Just be careful:

  • Too much tilt = eye strain
  • Not enough = limited reading access

Use pantoscopic and retroscopic tilt strategically to balance comfort and function.

Changing Lens Designs = Changing Patient Experience

People are creatures of habit.

Even switching to a new frame with the same lens design can feel different - because the software customizes each design per frame.

Switching brands or design philosophies entirely? That’s like going from Coke to kombucha. Each design has its own theory:

  • Some prioritize corridor width
  • Others minimize magnification effects

Don’t surprise your patients. If you’re changing the design, educate them first or risk frustration and failed adaptation.

Final Thoughts

Progressive lenses have never been more capable - but never more complicated. Success today isn’t just about measuring fitting height and plugging in a prescription.

It’s about understanding:

  • The impact of the data you provide
  • How design software interprets that data
  • The interaction between frames, prescriptions, and wear dynamics

And most of all, it’s about taking ownership of the design process so your patients get exactly what they need.

 

Need help navigating progressive lens fitting, measurements or troubleshooting? Let’s talk. We’re here to help you help your patients.