Every year, our technology gets better. Lenses correct more of the visual range, lasers are more precise, and outcomes that once seemed remarkable are now routine. So why is the proportion of eligible patients who choose surgery still so small?
Consider the numbers. Market Scope projected that premium IOLs would make up just under 17% of global units in 2025. Toric lenses tell a sharper story: they accounted for only 6% to 8% of cataract procedures, even though roughly 52% to 70% of cataract patients have enough astigmatism to qualify. In refractive surgery, one analysis estimated that even after a decade at peak volume, only 3.6% of eligible people in the UK had been treated. And in the US, where uptake is highest, only about 13% of eligible people have had laser refractive surgery. Better IOLs, push from surgeons will drive healthy premium growth +3
These are not the numbers of a saturated market. They describe a market where most of the demand has never been asked to move.
A clinical problem, or a system problem?
When adoption stalls, our instinct is to look for a clinical explanation and answer it with a better lens, a better laser, or a new indication. That work matters. But it rests on one assumption I'd challenge: the technology is what limits how many people choose surgery.
The Theory of Constraints, developed by Eliyahu Goldratt, says otherwise. Every system has one binding constraint that governs its output. Improve anything other than that constraint and total output does not change. A factory with a bottleneck at one machine gains nothing from speeding up the other machines around it.
Now think of the patient journey as a chain: awareness, trust, consultation, understanding of value, decision, and finally surgery. Clinical excellence sits at the end of that chain. If most eligible patients never reach it, then improving the last link does little for the number who arrive.
Where the chain breaks
The published evidence points to constraints that are not clinical.
Price and perceived value. In the 2015 ASCRS Clinical Survey, cost to the patient was the leading barrier to presbyopia-correcting IOL adoption, followed by concern over nighttime quality of vision. The second barrier is about expectations and trust, and expectations are set before the patient reaches the operating room.
The practice itself.Market Scope's David Harmon reported that about 25% of cataract surgeons offered neither presbyopia-correcting nor toric IOLs. His guess at the reason: lack of confidence in the technology, or lack of interest and skill in selling a premium service. In Goldratt's terms, that is a constraint inside the practice, and no advance in lens design will remove it.
Awareness. A patient who has worn glasses for decades has usually never been shown that another option exists. That is a communication problem, not a clinical one.
Five steps, applied to a practice
Goldratt gave a simple discipline for improving any system. Applied to patient adoption, it looks like this:
Identify the constraint. Measure each step of your patient journey, from inquiry to consultation to decision to surgery, and find where the largest share of eligible patients is lost. Don't assume it's marketing or price. Look at the data.
Exploit it. Before spending anything, get more from what you already have. If consultations are the constraint, improve how they are run: what patients hear, in what order, and how clearly the value is explained.
Subordinate everything else. Once you know the constraint, everything else in the practice should serve it. Advertising that floods a consultation process already at capacity makes things worse.
Elevate the constraint. Only after exploiting it do you add capacity through people, training, systems or investment.
Repeat. Fixing one constraint reveals the next. A practice that fixes consultation conversion will soon find that awareness or scheduling is now the limit. That is progress, not failure.
We use exactly this discipline with our customers. The order matters, and it is where most practices go wrong. The common response to slow growth is to buy something: a new laser, a bigger advertising budget, another marketing agency. Each is an investment in something that may not be the constraint, and this is why so much spending changes so little.
Saturation is often an illusion
A practice that has plateaued often concludes it has saturated its local market. Yet if only a small fraction of eligible patients in the region have ever been treated, what looks like saturation is more likely a bottleneck. The market isn't exhausted. The practice has reached the limit of what its current process can convert.
This is good news, because a bottleneck can be fixed and a saturated market cannot.
What this means for the field
We should be proud of the clinical progress in our specialty, and we should keep making it. But the next big gain in the number of patients whose vision improves is unlikely to come from a better device alone. It will come from finding the real constraint in the journey from "eligible" to "operated" and having the discipline to fix that first.
The patients are already there. The question is what stands between them and the outcome we already know how to deliver.
