Laser cataract surgery: what the laser actually does, and what the trials found
Laser cataract surgery is still cataract surgery. Here is the part the laser does, what the large trials and reviews found, and why "secondary cataract laser" is a different thing.
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I see parents and grandparents for squint, cataract and everyday eye problems, I operate on squint and cataract, and I perform LASIK, SMILE and Presbyond for adults, so one family can keep one eye doctor. Family eye care Where I practise
- Laser-assisted cataract surgery is still an operation. A Cochrane review says the femtosecond laser can make the corneal incisions, open the lens capsule and break up the cloudy lens, and the surgeon completes the rest.
- Two large randomised trials, FACT in the UK (785 adults) and FEMCAT in France (907 patients), did not find the laser better for vision or complications. FACT judged it not worse at three months; FEMCAT found it not superior.
- A 2023 Cochrane review of 42 trials found the two methods probably perform similarly. A 2025 meta-analysis of 46 trials found slightly better corrected vision with the laser at one week and no difference afterwards.
- Cochrane notes that most trials had unclear or high risk of bias and that 16 reported financial ties to the laser manufacturer, so the evidence is read with care in both directions.
- "Laser katarak sekunder" is a different laser. The YAG laser opens a cloudy capsule behind the new lens, months or years after any cataract operation, in about five minutes.
No. Laser cataract surgery is still cataract surgery. The laser does some of the steps, and the surgeon completes the operation and puts in the new lens. This page goes through what the laser does, what the large trials and reviews found when they compared it with the ordinary method, and what "laser katarak sekunder" means, which is a different laser altogether.
It is for the son or daughter who has been told Ah Ma can have "the laser option", and wants to know what that means before deciding anything. Whether drops or a laser could replace the operation is answered in what helps and when surgery is due, so this page starts after that point: Ah Ma needs the operation, and the question is which way it is done.
What does the laser actually do in cataract surgery?
It takes over some of the early steps. A Cochrane review of laser-assisted cataract surgery says the femtosecond laser can make the corneal incisions, open the front of the lens capsule and break up the cloudy lens. The surgeon then finishes the operation, which in these trials still included the ultrasound step, and places the new lens. The NHS describes that ultrasound step as breaking up the lens so the pieces can be removed by suction.
So there is no "laser removes the cataract" step. In FEMCAT, a French trial, most of the complications counted in the laser group happened during the ultrasound step or after surgery, not during the laser step. The laser is a cutting and softening tool at the start, and everything after it is the same operation described in choosing the lens for Ah Ma's cataract operation.
The American Academy of Ophthalmology says surgeons make the incisions by blade or by laser. The difference between the two methods is therefore who or what makes those first steps, the surgeon's hand or the laser.
What did the trials find when they compared the two?
For vision and complications, the large studies found little or no difference. Four pieces of evidence matter most: two big randomised trials, FACT and FEMCAT, and two reviews that pool many trials, one from Cochrane in 2023 and one in Scientific Reports in 2025.
FACT was run in three NHS hospitals in the United Kingdom and randomised 785 adults with age-related cataract, 392 to the laser and 393 to the ordinary method. At three months, unaided distance vision differed by 0.01 logMAR, a tiny amount, and the study judged the laser not worse.
Two posterior capsule tears happened, both in the ordinary group. Complications during surgery were 2.8 percent with the laser and 1.3 percent without, a gap the study did not count as significant, and the authors noted that FACT was not large enough to detect rare complications.
FEMCAT was run in five French university hospitals and randomised 907 patients with 1,476 eyes. It asked a stricter question: did the laser give a better "success" at three months, with success defined as no severe complication, sharp corrected vision, a refractive error within 0.75 dioptre and stable corneal astigmatism? Success was 41.1 percent with the laser and 43.6 percent with the ordinary method. The laser was not superior.
The Cochrane review of 2023 pooled 42 trials, 7,298 eyes in 5,831 adults. It found the two methods probably perform similarly for complications, vision and quality of life. Corrected vision at six months or longer was very slightly better with the laser, about one letter on the eye chart, which the review said is unlikely to matter in daily life.
Posterior capsule tears were possibly fewer with the laser, about four fewer per 1,000 operations, but that finding was low certainty. The 2025 Scientific Reports meta-analysis pooled 46 trials, 8,871 eyes. Corrected vision was better with the laser at one week and no different after that, and overall complications did not differ.
Is laser cataract surgery better than ordinary cataract surgery?
The studies cited here do not show that either method is better for most people. The laser can be more precise in the steps it does, and that is real, but the trials above did not turn that precision into a clear gain in sight or safety. This page does not weigh cost, which differs from centre to centre.
Two cautions come with the evidence itself. The Cochrane review notes that most of its 42 trials had unclear or high risk of bias, and that 16 of them reported financial ties to the laser manufacturer. It also says many studies measured narrow technical outcomes, not what the patient sees and feels. Neither point means the laser fails. They mean the evidence should be read with care in both directions.
A review by Kanclerz and Alio in the European Journal of Ophthalmology lists the drawbacks as laser-specific capsule complications, a risk of the pupil narrowing during surgery, and a learning curve for the surgeon.
The same authors suggest some patients may gain, such as people with few endothelial cells (the cells that keep the cornea clear) or those planning multifocal lenses, and say the advantage may not show in every routine case. That is the authors' suggestion, not a finding of a trial, and it is a question for the surgeon who has examined Ah Ma's eye.
What is "laser katarak sekunder"? Is it the same laser?
No. "Secondary cataract" is the name families use for a cloudy capsule behind the new lens, and it is treated with a different laser, the YAG laser, after the operation, not during it. The cataract itself does not come back once the cloudy lens has been taken out. The thin membrane that holds the new lens can turn cloudy weeks, months or years later, and the sight blurs again.
The American Academy of Ophthalmology says the YAG laser opens this membrane in about five minutes, usually once per eye, and sight should improve within about 48 hours if nothing else is wrong. This applies after any kind of cataract surgery, with or without a laser in the operation. The step-by-step explanation is in the lens page, in the section on clouding later.
The practical point is simple. If Ah Ma says the fog has come back months after her operation, book an eye check. Do not assume the first operation failed.
How long does laser cataract surgery take, and is recovery different?
The studies do not show a reliable saving of time. Across 11 trials in the Cochrane review, operating time ranged from three minutes faster with the laser to eight minutes faster with the ordinary method, and the certainty was low. The NHS says the operation usually takes 20 to 45 minutes, usually under local anaesthetic, and most people go home the same day.
On recovery, the 2025 meta-analysis found slightly better corrected vision with the laser at one week, then no difference. Vision after any cataract operation is blurry at first and improves over several days, and the drops, the care of the eye and the warning signs are the same. The first two weeks at home are in after Ah Ma's cataract operation.
A sudden shower of floaters, flashes of light, a dark curtain across the sight, or sudden blurring or pain after any eye operation needs urgent care, as the NHS notes, because it can be a detached retina.
What should we ask the surgeon about the laser?
Ask which steps the laser would do for her eye, why it is or is not suggested, and what the plan is for the lens. The answers depend on her eye, and only an examination tells the surgeon. Take the same questions to any surgeon, in a government hospital or a private one, as set out in Ah Ma's cataract: government or private.
Useful questions are short. Is the laser an option for her eye, or does something about her eye make it less suitable? What does the surgeon expect it to change for her, if anything? If the laser is not used, is the operation otherwise the same? Fees and what they include are a separate conversation with the centre, and this page does not discuss them.
Dr Chan Li Yen sees adults for cataract and general eye care, and she operates on cataract. The whole-family picture is in can a paediatric ophthalmologist see adults. This page is general information. The choice of method is made between Ah Ma and her surgeon after an examination.
- Floaters, flashes of light or a dark curtain across the vision appear suddenly, after any cataract operation or YAG laser, which can be a sign of a detached retina.
- Vision suddenly blurs, or the eye becomes painful and red, after cataract surgery.
- A baby has a white spot in the pupil.
Common questions
Does the laser remove the cataract?
Is laser cataract surgery better?
How long does laser cataract surgery take?
What is laser katarak sekunder?
Does the laser fix astigmatism better?
Who should decide whether Ah Ma has the laser?
- Cochrane 2023 · Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery · pubmed.ncbi.nlm.nih.gov (opens in a new tab)
- Scientific Reports 2025 · Femtosecond laser-assisted versus conventional phacoemulsification cataract surgery, meta-analysis of randomized controlled trials · pubmed.ncbi.nlm.nih.gov (opens in a new tab)
- Ophthalmology 2020 · FACT: femtosecond laser-assisted cataract surgery versus phacoemulsification, a randomized noninferiority trial · pmc.ncbi.nlm.nih.gov (opens in a new tab)
- The Lancet 2020 · FEMCAT: femtosecond laser-assisted versus phacoemulsification cataract surgery · pubmed.ncbi.nlm.nih.gov (opens in a new tab)
- European Journal of Ophthalmology 2021 · The benefits and drawbacks of femtosecond laser-assisted cataract surgery · pubmed.ncbi.nlm.nih.gov (opens in a new tab)
- American Academy of Ophthalmology · What is cataract surgery · www.aao.org (opens in a new tab)
- American Academy of Ophthalmology · What is a posterior capsulotomy · www.aao.org (opens in a new tab)
- NHS · Cataract surgery · www.nhs.uk (opens in a new tab)