The Human Algorithm

Every refractive surgeon remembers at least one patient whose surgery was technically perfect but who still left disappointed.

The refraction was close to plano. Visual acuity was excellent. The surgery itself was uncomplicated. Yet sitting across the desk at the postoperative visit, the patient quietly says, “Doctor, I thought I would see better.”

I have had those conversations, and they never stop being uncomfortable—because they challenge the way we define success. If the surgery was successful, why isn’t the patient happy?

The answer, I believe, is that refractive surgery has evolved faster than the way we make decisions about it. Success is no longer measured solely by visual acuity or refractive accuracy. It is measured by how closely the postoperative result aligns with the patient’s expectations, lifestyle, and visual priorities.

At the same time, our specialty has entered an extraordinary era of innovation. Sophisticated biometry, premium intraocular lenses, advanced laser platforms, and, increasingly, artificial intelligence allow us to plan surgery with remarkable precision. We can measure almost every aspect of the eye and predict outcomes better than ever before. Yet one of the most important questions remains exactly the same: which procedure is truly the right one for this patient?

Technology tells us what we can do. Clinical judgement tells us what we should do.

The longer I have practised refractive surgery, the more I have realised that the most challenging decisions rarely depend on keratometry, axial length, or corneal tomography alone. They depend on understanding the person sitting in front of me. That realisation gradually changed the way I approach every consultation: instead of beginning with the eye, I found myself beginning with the patient.

Over time, these reflections evolved into a simple framework that now guides every refractive consultation in my practice—a concept I recently had the opportunity to present during the ESCRS Refractive Surgery Masterclass in a session on patient expectations and the final surgical decision. I now think of it as ‘the Human Algorithm’.

Unlike biometric algorithms, the Human Algorithm does not calculate lens power or recommend a specific procedure. Instead, it structures the clinical thinking that takes place before any recommendation is made. It begins with five simple questions.

WHO is this patient?

Every consultation begins with a person, not an eye. Age, refraction, and corneal measurements are essential, but they rarely tell the whole story. Patients arrive with different personalities, different motivations, and very different levels of tolerance for visual compromise.

Some readily accept trade-offs if it means spectacle independence. Others notice the smallest imperfection and may never fully adapt to dysphotopsia or reduced contrast sensitivity. Some seek reassurance as much as surgery, while others arrive having already decided what they believe they need. Understanding the patient behind the measurements is the first step toward an appropriate recommendation.

WHY are they seeking surgery now?

The second question often changes the consultation completely. Patients rarely come asking for LASIK, a phakic IOL, or refractive lens exchange. They come because they want something in their lives to be different.

Perhaps presbyopia has started affecting their work. Perhaps contact lenses have become uncomfortable after years of successful wear. Perhaps they simply want the freedom to travel, exercise, or enjoy everyday life without depending on glasses. When we understand the motivation behind the visit, we are better able to determine whether surgery is truly the right solution—or whether a different recommendation may better serve their long-term interests.

HOW do they use their vision?

Visual acuity is measured in the clinic. Vision is experienced everywhere else.

A surgeon, a professional driver, a graphic designer, and an avid golfer may all have healthy eyes, yet they rely on their vision in completely different ways. Lifestyle is therefore not a secondary consideration; it is central to refractive decision making. Understanding how patients actually use their vision allows us to move beyond correcting refractive error and begin addressing functional vision.

In my experience, these conversations also build trust. Patients quickly recognise that the consultation is not about fitting them into a procedure but about finding the procedure that genuinely fits them.

WHAT outcome are they truly expecting?

This may be the most important question of all. Patients do not simply expect better vision. They expect a better life.

Some imagine never wearing glasses again. Others expect vision that feels younger than it has for decades. Many arrive influenced by friends, social media, or advertising, with expectations that are optimistic but not always realistic. Managing expectations has long been considered essential in refractive surgery, but I believe a more accurate goal is to align expectations rather than simply manage them.

The consultation should not lower expectations unnecessarily nor promise outcomes that current technology cannot consistently deliver. It should create a shared understanding of what success will look like for that individual patient. When surgeon and patient define success differently, disappointment becomes almost inevitable.

CAN today’s technology realistically deliver it?

This is the point at which objective clinical findings finally take centre stage. Corneal tomography, ocular surface health, pupil size, lens status, retinal pathology, and countless other factors all contribute to the final recommendation. Not every patient is an ideal candidate for every procedure, and not every visual goal can be achieved without compromise.

Technology is essential. But technology should confirm the decision—not make it.

One of the most valuable lessons I have learned is that saying ‘no’ can sometimes be the best refractive procedure we offer. Choosing not to operate, delaying surgery, or recommending a more conservative option may ultimately lead to the highest level of patient satisfaction, because every recommendation must satisfy two decision makers: the patient and the eye.

The eye has a vote

Throughout my career, one simple principle has remained constant: the eye has a vote.

Patients may desire complete spectacle independence. Surgeons may be enthusiastic about the latest technology. Industry continues to deliver remarkable innovations. Yet biology still defines the boundaries of what is possible. The best refractive decisions lie at the intersection of patient expectations and ocular reality. Neither should dominate the conversation; both deserve equal respect.

The final question

Refractive surgery has never been more sophisticated. Artificial intelligence will continue to improve diagnostics, imaging will become even more precise, and new lenses and laser platforms will expand our options in ways we can only imagine today. But no technological advance will replace clinical judgement. Every refractive consultation is ultimately a human conversation before it becomes a surgical decision.

For me, that conversation begins with five simple questions. Who is this patient? Why are they here? How do they use their vision? What outcome are they expecting? Can I realistically deliver it?

Only then do I ask the final question: What is the right procedure?

Because patients do not come to us asking for the newest technology. They come to us asking for the best decision.

And in the end, the best refractive surgeons are not those who perform the most advanced procedures but those who know when, and for whom, to perform them.

Başak Bostancı MD, FEBOphth is an Associate Professor of Ophthalmology specialising in cataract and refractive surgery at Dünya Göz Hospital, Istanbul, Türkiye. She presented this framework at the ESCRS Refractive Surgery Masterclass.