Cataract surgery: the procedure, the choice of lens, your decision

When an operation makes sense — and when not yet

Cataract surgery is not carried out to a fixed timetable. What decides it is not the medical findings alone, but how much your vision restricts your everyday life. Two people with the same clouding of the lens can therefore reach the right moment for the procedure at quite different times — one drives cross-country at night every week, the other reads by the window in daylight. What a cataract actually is, and how you notice it, is described on the parent page: how a cataract develops and how you recognise it. This page begins after the diagnosis, with the question of what to do now.

Typical reasons that bring people to us are, for example:

• Reading becomes increasingly tiring — it takes more and more light, and the glasses 'are never right any more', even after a change of lenses.
• Driving at dusk or at night feels unsafe. Headlights dazzle more than they used to, outlines blur, road signs appear later.
• Colours and contrast lose their clarity. White appears yellowish, blue shifts — often it is noticed only when the two eyes are compared directly.
• You feel visually restricted in everyday life and start giving things up: the evening drive, the needlework, the outing on your own.

Noticeably often there is one very specific ability at stake behind the appointment — driving, reading, independence. That is exactly what we measure the timing against: your life, not a measured value alone. In a thorough preliminary assessment we establish, without hurry, whether a cataract explains your symptoms at all and whether now is the right moment. Sometimes our answer is 'not yet' — and then we say so, instead of booking a date.

Conversely there are situations in which we advise an operation even though you are still managing well: when the clouding becomes so dense that the retina behind it can no longer be assessed, or when another disease of the eye makes regular examination of the back of the eye necessary. We give reasons for that too, rather than simply recommending it. And if you are unsure about a proposal from elsewhere, a second opinion is not a delicate request but a sensible one — the same rule on costs applies to that consultation as to any other.

How the operation goes: what happens on the day

Cataract surgery is among the most common procedures in modern medicine, and it is one of the most thoroughly documented: the European EUREQUO registry alone covers 2.85 million operations — that figure and the comparative values against which we measure our own results, with their sources, are on the overview page on cataract. For you as a patient that means one thing above all — the process is well practised, and there is no surprise in it that we could not explain to you beforehand.

Before the procedure

You come to the operation fasting — without exception, because being accompanied by the anaesthetist is the rule here and not the exception. As standard an experienced anaesthetist guides you into light sedation (propofol), from which you remain responsive; in addition the eye is numbed with drops and the pupil is dilated. That takes its time, and that time is planned for. Tell us beforehand if you are very tense, suffer from claustrophobia or do not tolerate lying flat — there are solutions for that, but only if we know about it.

The procedure itself

Through a very small opening at the edge of the cornea the clouded natural lens is broken up and aspirated; in its place goes the previously calculated intraocular lens, which is inserted folded through the same small opening and unfolds inside the eye. It then sits exactly where your own lens was — in the capsular bag, which is deliberately left in place and holds it where it belongs. This new lens stays in the eye permanently and cannot cloud over again. The incision is so small that as a rule it closes by itself and does not have to be stitched.

The procedure itself usually takes around twelve minutes where the findings are uncomplicated — markedly shorter than most people expect, and markedly shorter than the visit as a whole. You lie under an operating microscope; under sedation most people notice nothing of it, and if they do, then bright light and blurred movement, no details of what is being done. Pain is not to be expected; most people feel at most a slight sensation of pressure.

After the procedure, the same day

The eye is covered or fitted with a protective shield, you rest briefly, and then you go home — outpatient here really does mean outpatient. Do not drive yourself that day: arrange someone to accompany you, a taxi or public transport, and do it when you book the appointment. You are given the eye drops for the coming days, together with a written schedule of when to use which, and the dates for the follow-up. The first is as a rule the following day, the second after a week — with clear responsibility, not as anonymous routine.

Risks — named honestly, with a published figure

Cataract surgery is a very safe routine procedure. And even so: No medical procedure is without risk — anyone who tells you otherwise is selling you something. We talk it through with you openly and in plain words before you decide, not once you have signed.

Every clinic claims experience. So we show you the figure by which it is measured — the rate of serious intraoperative complications. For cataract operations by PD Dr von Rückmann, over 15'000 operations since 1994 including mature cataracts and pseudoexfoliation, it is 1 : 367, that is one complication in 367 operations, and around four times rarer than the European registry average. Basis: own case series, n = 5'823 operations, period 2019–2025, recorded as intraoperative complications with capsule rupture; last audited Q1 2026. Two limitations belong with it, so that the figure stays what it is. First, it is surgeon-specific and not a clinic-wide statistic — you are told by name beforehand who carries out your operation. Second, it measures what happens during the operation: infections, macular oedema, residual refractive error and posterior capsule opacification are not included; they are set out below. The comparative figures from the European registry and from a British comparative study, with their case numbers, are on the overview page on cataract, in the section on documented quality.

What is meant in detail. The most relevant complication during the operation is a tear in the lens capsule with vitreous loss; it makes the procedure more demanding and can require the intraocular lens to be placed differently. Infections inside the eye are very rare — they are the reason for the strict schedule of drops afterwards, and the reason an increasingly red, painful eye needs to be looked at straight away. Also possible are:

• Inflammatory reactions in the eye, which are treated with drops and as a rule subside.
• Changes in intraocular pressure in the first few days — one of the reasons pressure is measured at the follow-up. Anyone who is also being treated for glaucoma is monitored particularly closely here.
• Swelling at the point of sharpest vision (macular oedema), which can worsen vision temporarily and is treated. Uncommon.
• A residual refractive error. The calculation of the lens is precise, but no calculation hits every eye exactly. Where a deviation remains, it is as a rule corrected with glasses.
• A later clouding of the lens capsule (posterior capsule opacification) — not an incident during the operation, but a known later development. See the next section.

And the sentence that comes hardest in this section. Almost everything on this list subsides, is treated, or is corrected with glasses. Almost everything. An infection inside the eye or a very unfavourable course can mean that vision in that eye stays permanently worse than it was before the operation — in the extreme case considerably worse. That is rare, and it is the reason we do not recommend an operation while you are managing without one. Anyone who promises you certainty at this point is promising something nobody can keep.

Whether and how much these points weigh in your case depends on your eye: on the retina, on the cornea, on earlier inflammation, on how dense the clouding is and on other conditions. That is exactly what we talk about before the procedure — and what it means for your findings we tell you specifically, not as a formula.

What the operation can do — and what it cannot

The operation removes a clouding. It improves vision exactly as far as the clouding had restricted it — and not a step further. In most people that is a great deal, because the cataract was the limiting factor. It is less where something else is also in the way, and that then belongs before the operation and not after it:

• An age-related macular degeneration (AMD) affects the point of sharpest vision. The operation does not improve it — what improves is everything the clouded lens was additionally hiding.
• A Glaucoma costs visual field, and lost visual field does not come back. The two conditions often occur together; they are treated separately. What treatment glaucoma needs in its own right, from pressure-lowering drops through the SLT laser to surgery, is set out on its own page.
• An diabetic retinal disease can become more active around the time of the operation, and swelling at the point of sharpest vision then occurs more often. Sometimes it only becomes visible at all once the clouding is gone. We therefore assess the retina beforehand and schedule the follow-up appointments more closely afterwards.
• A pre-existing weakness of the innermost layer of the cornea (Fuchs' dystrophy) tolerates the operation less well: the cornea can take longer afterwards to become clear again and, in unfavourable cases, stay clouded permanently and require treatment of its own. We measure that layer at the preliminary assessment; where the finding is borderline, we tell you before you decide.
• A dry eye can be more noticeable for a while after the operation. That can be treated — see the page on dry eyes.

And glasses. An intraocular lens does not accommodate. With a monofocal lens you will therefore need a correction for one distance, usually for reading; with an EDOF or multifocal lens less often, but not reliably never. Freedom from glasses is a goal one can aim for — it is not a result that can be promised, and anyone promising it to you is going beyond what a lens can do.

What the procedure does actually give back to the great majority of people is more concrete than any percentage: colours that are colours again. Night drives that no longer feel like an obstacle course of glare. Reading without the extra lamp. And for many the independence that goes with driving. Cataract is one of the few eye conditions in which a loss of this magnitude as a rule stays reversible.