Cataract surgery: how it works, implants and recovery

When should a cataract be operated on?

A cataract is a loss of transparency in the natural lens, the lens sitting behind the iris. It often appears gradually with age, but it can also arise in other contexts. You may notice a mist over your vision, less vivid colours, increased sensitivity to headlights or changes in your correction. These signs call for an examination, because they are not enough to establish the diagnosis.

The indication rests on how much it disturbs your daily life. Reading, recognising a face, working or driving safely enough does not demand the same abilities from everyone. Acuity that is still reasonable in the consulting room can coexist with severe glare. Conversely, an early cataract can be monitored if it does not limit you and creates no particular medical difficulty.

There is no need to systematically wait for a cataract to be ‘ripe’. The right moment is discussed with the ophthalmologist, weighing the expected benefit against the risks. An operation may also be proposed when the opaque lens prevents the back of the eye from being examined or treated. The French health insurance service distinguishes between these indications and points out that surgery is the treatment for an established cataract.

A new pair of glasses or better lighting can improve certain activities for a while. They do not make a clouded lens transparent again. No food supplement or ordinary eye drop replaces extraction when it is indicated. If you prefer to postpone, ask what monitoring to plan and what changes should bring you back for an appointment.

The assessment: checking the cause of reduced vision

Examining the eye as a whole

The assessment is not limited to recording a cataract. The ophthalmologist measures your vision, examines the cornea and the lens, checks the pressure and studies the retina as far as this is possible. Macular disease, glaucoma or damage linked to diabetes can explain part of the problem. The operation may still be worthwhile, with a less complete improvement than in an eye with no other condition.

Imaging of the macula may be requested in order to analyse the retinal area used for fine vision. In some very opaque cataracts, examination of the back of the eye remains limited. The practitioner should explain what can be predicted and what remains uncertain. Imperfect visibility before the procedure must not be turned into a promise of complete recovery.

Your history counts: an old injury, inflammation, high short-sightedness, retinal surgery or glaucoma treatment can change the operation and its follow-up. Also mention LASIK or any other corneal surgery, however long ago. The data from that operation can help to calculate the implant and to interpret your current measurements.

Measuring the eye to calculate the implant

Biometry gathers the dimensions of the eye, including its length, and measurements of corneal curvature feed into the calculation. The surgeon chooses an implant power matching the target discussed with you. Despite the precision of these examinations, a residual correction remains possible. The calculation does not guarantee complete independence from glasses.

The quality of the tear film and the regularity of the cornea influence how reliable the measurements are. Dryness or inflammation of the eyelids may call for treatment beforehand. If you wear contact lenses, follow the period of interruption indicated before the assessment. Repeated measurements can be useful when the readings do not agree.

Which implant should you choose during cataract surgery?

Monofocal: deciding which distance comes first

The monofocal implant essentially favours one distance. The common choice is to aim for distance vision, with glasses for reading. A short-sighted person may prefer to keep comfortable near vision and wear a correction for distance. This decision must be explicit before the operation, because it shapes your daily life once the cataract is gone.

It is sometimes possible to share the targets between the two eyes in order to widen the range of usable distances. This micro-monovision has to take account of your visual balance and your activities. A difference in correction that one person tolerates well can trouble another. Simply wishing to wear glasses less often is not enough to define a target.

Toric, multifocal and extended depth of focus

A toric implant corrects astigmatism. Its value depends on the corneal measurements and on the optical plan. Multifocal implants seek to provide several viewing distances, while extended depth of focus implants aim at a wider range of sharpness, often useful for intermediate vision. The results differ according to the model and to the characteristics of your eye.

Greater independence can come with halos, glare or a compromise on contrast. Some eye diseases make multifocality less attractive. The guide to the multifocal implant explains these choices, which have to be weighed against your priorities, particularly night driving and reading.

The Société française d’ophtalmologie sets out the limits of so-called premium implants and the prospect of additional corrections. A price supplement therefore does not mean that an implant is preferable for every eye. Also ask which solution would be chosen if a difficulty during the operation prevented the model initially planned from being fitted.

Preparing for the operation without changing your medication on your own

Pass on the full list of your medicines, including prostate treatments, anticoagulants, eye drops and supplements. Some medicines can influence how the operation goes or how it is organised. Do not stop any treatment without medical instruction: the decision belongs to the team, which knows your general situation and the procedure planned.

Tell the centre about any allergy, breathing problem, persistent cough, strong anxiety or difficulty lying flat. These points can lead to the positioning or the anaesthetic being adapted. Reduced mobility and difficulty putting in drops should also be anticipated so that your journey home and care at home can be organised.

Instructions on fasting, hygiene and taking medicines are given by the centre according to the type of anaesthetic. Apply the ones you are given, rather than a protocol found online. Arrange for someone to accompany you and for suitable transport. You will not be driving yourself home after the operation.

Before the planned day, check that you have understood which eye will be operated on, the correction target and the follow-up schedule. Keep the centre’s contact details to hand. If you live alone, organise help for the first practical tasks or for the eye drops when putting them in is difficult.

What happens during cataract surgery?

Anaesthetic and positioning

Surgery is generally carried out under local anaesthetic, often with drops, sometimes supplemented by another method depending on the case. You usually stay awake. Sedation may be offered; a general anaesthetic answers particular indications. The team should explain the choice made and the sensations you may feel.

A device holds the eyelids open, while a sterile drape protects the area. The surgeon operates under a microscope. You may perceive light and movement, without seeing the detail of the procedure. Say if you are in pain or need to cough so that the team can guide you; avoid any sudden unannounced movement.

Removing the lens and fitting the implant

The surgeon makes a small opening, then reaches the envelope of the lens, known as the capsule. In phacoemulsification, an ultrasound probe breaks up the opaque lens and allows it to be aspirated. The capsule is usually kept largely intact so that it can support the new implant.

The foldable implant is introduced and then unfolded inside the eye. The final steps include checks and the measures intended to limit infection according to the protocol. An unforeseen difficulty can require the procedure or the implantation to be adapted. The exact technique and the duration vary with the complexity of the cataract and the state of the eye.

The operation itself is often short, but your stay at the centre includes preparation, the anaesthetic, monitoring and discharge formalities. Day-case care means that you generally go home the same day, not that the whole procedure lasts only a few minutes. Discharge depends on the check-up and on your general situation.

What part does the laser play?

A femtosecond laser can assist certain steps, in particular opening the capsule and breaking up the lens beforehand. It does not turn the whole operation into an external treatment with no incision. Fitting the implant and the other surgical stages are still required.

The Cochrane review of laser-assisted surgery shows no systematic, clinically important benefit over conventional phacoemulsification on the main outcomes studied. So ask what this option brings in your own situation, and what it might cost extra. Surgery without femtosecond assistance remains a standard technique.

After the operation: what is common and what should alert you

Initial blurring, a gritty sensation, watering or sensitivity to light can occur. Vision often improves gradually. Brighter colours can come as a surprise once a yellowed lens has been removed. The speed of recovery varies, particularly when the cornea is temporarily swollen or when another eye disease is present as well.

The eye drops prescribed must be used according to the schedule you are given. Wash your hands and avoid touching the eye or the lashes with the nozzle. If several products are prescribed, ask what interval to leave between them. Do not extend or stop a treatment on your own because your vision seems satisfactory.

Severe pain, a drop in vision, marked redness or rapid worsening call for urgent advice. New flashes of light, numerous floaters or a dark curtain also need assessment without delay. The post-operative information from the National Eye Institute sets out these signs and the importance of check-ups.

The follow-up appointment allows the eye to be examined, the pressure to be checked and care to be adjusted. Discomfort is not judged by its intensity on a scale alone: how it changes, and whether it comes with reduced vision, both count. If you are unsure about a new symptom, contact the team rather than waiting for the next scheduled consultation.

Going back to your activities, driving and new glasses

Reading and quiet activities can often be resumed according to your comfort and to medical advice. Temporary eye strain does not necessarily mean a complication. You can adjust the lighting and how long you spend on an activity. The restrictions mainly concern protecting the eye and situations likely to disturb healing.

Avoid rubbing and follow the instructions about the protective shield, water in the eye, make-up, swimming and physical effort. Going back to sport depends on the procedure, on your examination and on the risk of injury. Your practitioner should give you the intervals that suit you, rather than applying the same timetable to everyone who has been operated on.

Driving requires sufficient vision and a satisfactory balance between the two eyes. After the first operation, a large difference in correction can disturb your perception of distance. The ophthalmologist will tell you when to start again and how to manage your temporary eyewear. A mere impression of improvement is not enough to justify driving at night or for work.

Your final glasses are generally prescribed once things have stabilised. The interval depends on how the eye develops and on whether the second side is already scheduled. A reading correction may still be needed with a monofocal implant, and occasional glasses can be useful with other implants. This possibility should be planned for from the pre-operative consultation onwards.

Operating on both eyes: how is the timetable decided?

When both eyes have a cataract, the difficulty they cause may differ. The ophthalmologist decides with you on the order and organisation of the operations. The second eye is not automatically operated on immediately after the first. The centre’s usual practice, your risk factors and the initial result all contribute to setting the timetable.

Surgery on both eyes on the same day may be offered in certain situations and certain centres, with specific protocols. Other pathways separate the operations. The ESCRS patient portal presents these possibilities. Ask why the arrangement proposed suits your case and how each eye would be followed up.

Between the two procedures, mention any difficulty on stairs, in front of a screen or when moving about. It may come from the temporary imbalance between your eyes. A provisional optical solution can be discussed. If the first eye develops unusually, that should be examined before continuing with the pathway initially planned.

The possible complications and what they mean

Serious complications are uncommon, but cataract surgery does carry risks. An infection inside the eye, known as endophthalmitis, can threaten vision and requires urgent care. Retinal detachment, macular swelling, a marked inflammatory reaction or an abnormality of pressure can also occur.

During the procedure, a weak or torn capsule can change the options for fitting the implant. Other complications involve the cornea, the centring of the implant or a correction that differs from the one expected. Some are treated with medicines, others require a further operation. Your personal risk depends among other things on associated diseases and on your history.

An incomplete improvement does not always mean that the operation failed technically. A disease of the macula or of the optic nerve can limit vision despite a well-positioned implant. The initial assessment and the check-ups serve to separate these mechanisms. Ask for an explanation based on the examination if your recovery does not match what you were told to expect.

Can a cataract come back after the operation?

The lens that has been removed does not grow back. The capsule kept behind the implant, on the other hand, can become cloudy after a certain time. This posterior capsule opacification, often called a secondary cataract, can create an impression of haze or glare. It is not the only possible cause of a late drop in vision.

When it explains the problem, the ophthalmologist can propose opening the capsule with a YAG laser. This procedure is different from the original operation: it does not involve removing another lens. It has its own precautions and its own follow-up. The indication has to be confirmed, particularly if a problem with the implant is also being considered.

Any new loss of vision therefore deserves a consultation. The implant offers no protection against retinal ageing, glaucoma or the other diseases of the eye. Your follow-up still matters several years after a successful operation. Keep the implant reference and the operation report to make future examinations easier.

Cost, reimbursement and organising your care

The quote should separate the operation, the fees, the anaesthetic and any supplements for the implant or the technique. What remains yours to pay depends on the hospital, the practitioner, your insurance and the options chosen. A medically indicated operation and an option intended to reduce your glasses further do not necessarily fall under the same financial terms.

Have the amounts checked with your health insurer and your top-up insurance before the planned date. A price quoted should state whether it covers one eye and which check-ups are included. Ask how additional examinations or a further operation would be billed, without assuming that they will be needed. These questions let you compare proposals that cover the same content.

For an operation far from home, plan for local follow-up, for transport and for the possibility of extending your stay if the examination calls for it. Obtain a legible report and a medical contact you can use once you are back. The various forms of eye surgery do not all impose the same restrictions: your timetable should be based on the procedure actually carried out and on the check-ups.

Before deciding, you should be able to restate three things: why the operation is worthwhile now, what vision the implant is meant to give you, and which symptoms will call for a prompt consultation. These answers give consent a concrete shape. They let you approach a common operation with precise expectations, without playing down its limits or the monitoring it needs.

Sources

1. Assurance maladie. (2025, December 5). Traitement de la cataracte : quand faut-il être opéré ?.
2. National Eye Institute. (2024, December 5). Cataract surgery.
3. European Society of Cataract and Refractive Surgeons. (n.d.). Chirurgie de la cataracte.
4. Société française d’ophtalmologie. (2026). Implants premiums. Fiche d’information 1C.
5. Narayan, A., Evans, J. R., O’Brart, D., Bunce, C., Gore, D. M., & Day, A. C. (2023). Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery. Cochrane Database of Systematic Reviews, 6, CD010735.