Katarakt.Information

How cataract surgery works

Cataract surgery, the removal of the clouded natural lens of the eye, is the most frequently performed planned operation worldwide, and one of the safest. It takes 15 minutes on average, is carried out under anaesthetic eye drops and requires no hospital stay. Most patients already see noticeably better the next day.

15 min
average duration
Drops
instead of an injection for anaesthesia
outpatient
no hospital stay
24–48 h
until vision improves

The three core steps of the procedure

Illustration: forceps open the front lens capsule in the eye (capsulorhexis)
Capsulorhexis
Opening the lens capsule
Illustration: an ultrasound probe breaks up the clouded lens and aspirates it (phacoemulsification)
Phacoemulsification
Ultrasound breaks up the clouded lens
Illustration: a folded artificial lens (IOL) is inserted into the capsular bag
IOL implantation
The artificial lens is inserted

No need to fear the anaesthesia

In over 95% of cases the eye is numbed with anaesthetic eye drops alone: no injection, no general anaesthesia. You stay awake during the procedure, but all you need to do is keep still. You see light and movement, but no details of the procedure itself.

Anaesthetic drops
Standard (>95%)

Numbing eye drops. No needle, no patch. You are awake and cooperate actively.

Injection beside the eye
When needed

For restless patients or more complex procedures. The eye is completely immobilised.

General anaesthesia
Very rare

Only for children or when cooperation is not possible. The exception in adults.

Step by step: what happens during the operation?

The whole procedure takes 10–20 minutes. You are typically at the hospital for 2–4 hours, including preparation and monitoring afterwards.

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FLACS: what the laser actually adds

In femtosecond laser-assisted cataract surgery (FLACS), a laser takes over opening the lens capsule, making the incisions and pre-fragmenting the lens. That sounds like a clear advantage over the manual method, yet independent research paints a more sober picture.

What the studies say

The 2023 Cochrane Review (42 randomised trials) and a 2025 meta-analysis (46 studies, 8,871 eyes) reach the same conclusion: for routine procedures there is no clinically meaningful difference in visual acuity, complication rate or healing between FLACS and conventional phacoemulsification. A marginally better visual acuity after one week (FLACS) evens out completely within a month at the latest.

Sources: Cochrane Database Syst Rev 2023, CD010735 · Scientific Reports, Feb 2025 (doi: 10.1038/s41598-025-13174-1)

Possible advantages of FLACS
  • ·Geometrically more precise capsule opening, relevant for premium lenses (trifocal and toric IOLs)
  • ·Slightly less ultrasound energy in the anterior chamber
  • ·Posterior capsule rupture somewhat less frequent (4 in 1,000 operations according to Cochrane)
What speaks against it
  • ·Out-of-pocket payment of €500–1,000 per eye, not covered by public insurance
  • ·No proven long-term benefit for standard cases
  • ·Not available at every clinic
  • ·Longer overall procedure time
When FLACS can make sense: when a premium lens (trifocal or toric IOL) is planned, where an exact capsule opening improves lens centring, and when you are prepared to carry the extra cost. For standard surgery with a lens covered by public insurance, conventional phacoemulsification is equivalent according to current research.

Your day around the operation

What to expect from arrival to the trip home:

Before arrival

Preoperative eye drops (if prescribed by your doctor), no make-up, arrange for someone to drive you home.

Arrival

Admission and a final check of the eye. Pupil-dilating drops are given; this takes 20–30 minutes.

Preparation

Changing, sterile draping, anaesthetic drops. You lie relaxed on the operating table.

10–20 minutes of surgery

The procedure itself. You see light and colours, but no details. It is usually completely painless.

Recovery room

Brief monitoring, eye drops, a first check by the doctor. An eye shield is fitted.

Trip home

Someone drives you home. Do not drive on the day of surgery. Rest at home.

Checklist: what do I need to bring on the day of surgery?

All the important points for the day of the operation, to print out or save on your phone (PDF, in German).

Download PDF
Discuss the procedure in person?

An experienced surgeon explains every step to you and answers your questions. Find a specialist near you.

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Medically reviewed information
Last updated: April 2026 Sources: ESCRS (European Society of Cataract and Refractive Surgeons), ÖOG (Österreichische Ophthalmologische Gesellschaft), gesundheit.gv.at