Multifocal implants: benefits, drawbacks and how to choose

What is a multifocal intraocular lens for?

The natural lens, or crystalline lens, is the eye’s own lens, sitting inside the eye. When it turns opaque, the cataract obstructs the passage of light. Removing it generally requires an intraocular implant to be fitted, which takes on part of the focusing previously done by the natural lens. The power and the characteristics of that implant are chosen before the operation.

A monofocal implant essentially has a single point of sharp focus. If it is calculated for distance vision, glasses are usually still needed for reading. A multifocal implant organises several focal points, so as to provide usable vision at different distances. It does not reproduce the accommodation of a young natural lens: it relies on a fixed optical design and on the way your visual system uses the images it receives.

The term ‘multifocal’ covers several designs. Bifocal implants generally favour distance and near vision; trifocal implants add an intermediate distance. The distances that are genuinely comfortable depend on the model and on your eye. So ask what the implant under consideration should allow for your screen, your book or your close-up manual work, rather than accepting a general promise of vision at every distance.

The implant is placed inside the eye during an operation. It is different from a multifocal contact lens, which sits on the cornea and can be removed. It is also different from a phakic lens, which leaves the natural lens in place. Operations on the natural lens and the fitting of phakic lenses both belong to eye surgery, but their indications and their risks do not overlap.

Multifocal, monofocal, EDOF and toric: understanding the differences

The monofocal implant favours one distance

With a monofocal implant, the target can be set for distance vision or for closer vision. Some short-sighted patients prefer to keep the ability to read without glasses and accept a correction for distance. The choice of target should be discussed explicitly: the phrase ‘standard implant’ does not on its own describe the vision you can expect.

A monovision or micro-monovision strategy can use monofocal implants calculated differently between the two eyes. One favours distance, the other closer vision. This combination can reduce the need for glasses without multifocality in each eye, but it brings its own trade-offs, particularly for depth perception and for certain demanding visual tasks.

The multifocal implant widens the range of usable distances

Multifocal implants aim at greater visual independence. That can cover reading a phone, intermediate activities and distance vision, without any single model necessarily excelling in every situation. Good lighting remains important for small print. You may also need a correction for one specific task even though the overall result is judged satisfactory.

The Cochrane review of multifocal implants found less dependence on glasses than with monofocal implants, at the cost of more unwanted light effects such as halos. It covers a variety of studies and models, however, with a search that stopped in 2016. Its conclusions shed light on the general trade-off without predicting how a current implant will perform for one individual.

EDOF and toric implants answer other criteria

EDOF implants, with extended depth of focus, seek to widen the range of sharpness, particularly between distance and intermediate vision. They can represent a compromise when priority is given to screen work, with a correction still needed to read small print. The designs vary: the EDOF label is not enough to claim an absence of halos, or the same near vision, across all models.

A toric implant corrects astigmatism. It can be monofocal, multifocal or belong to another family. ‘Toric’ and ‘multifocal’ therefore describe two different properties. If you have astigmatism, ask how it will be taken into account, because a residual correction can reduce the benefit of an implant intended to cut down your use of glasses.

Which patients may a multifocal implant suit?

The choice rests first of all on an eye whose other structures allow sufficient visual quality. The ophthalmologist studies the cornea, the tear film, the retina and the optic nerve. Macular damage, certain forms of glaucoma, an irregular cornea or marked dryness can limit the value of multifocality. The decision depends on their nature and severity, and sometimes leads to a preference for a monofocal implant.

Your activities also shape the discussion. Someone who drives at night for long periods may place more weight on contrast and on the absence of halos. Another person may give priority to occasional reading without glasses. The point is not to rank these expectations: the surgeon needs to know which one takes priority when several qualities cannot all be maximised at once.

Difficulty using both eyes together, a long-standing squint or amblyopia also deserve to be mentioned. The result depends on binocular vision, and not only on the acuity measured in each eye. When you already have an implant in one eye, its model and the vision obtained with it have to be built into the plan for the other eye.

The information sheet on premium implants from the Société française d’ophtalmologie stresses patient selection, the possible side effects and the prospect of additional treatments. Declining a multifocal implant may therefore amount to a recommendation about visual quality, even when cataract surgery itself remains indicated.

Cataract and clear lens: two different decisions

When a cataract disturbs your daily life, the operation is first of all intended to remove an opacity. The multifocal choice is added to that therapeutic indication. Even so, it is worth checking how much of your reduced vision comes from the natural lens: another disease can limit the improvement, even if the extraction goes normally.

In clear lens surgery performed for refractive reasons, the natural lens is removed mainly to reduce dependence on glasses. The benefit has to be weighed against the irreversible nature of that extraction. In someone who still has useful accommodation, it is lost. Retinal risk, particularly in some highly short-sighted eyes, calls for a particularly careful discussion.

Age alone does not decide the indication. An early cataract, marked long-sightedness, corneal constraints or troublesome presbyopia can all guide the thinking, but each element has to be placed back within the full examination. Carrying on with glasses or contact lenses is one of the alternatives. An elective operation can be postponed when the trade-off does not suit you.

If your question is mainly about the operation itself, the details of the cataract operation make it easier to separate the surgical steps from the choice of implant. Multifocality does not, on its own, call for surgery carried out ‘entirely with a laser’.

The assessment before choosing your implant

Precise measurements to calculate its power

Biometry measures the dimensions of the eye; corneal measurements describe its power and its astigmatism. These data feed into the calculation of the implant. The result is still subject to margins of uncertainty: healing, the final position of the implant and anatomical particularities can leave a small residual correction.

Dryness or an unstable tear film can disturb the measurements. The ophthalmologist may suggest treating the ocular surface before starting the assessment again. If you wear contact lenses, respect the period of interruption indicated by the team. The aim is to obtain reproducible data, rather than choosing an implant from a measurement that is not reliable enough.

Any history of corneal laser surgery has to be known, however long ago it was. Changes in curvature can make the calculations more delicate and influence whether a multifocal implant is appropriate. Bring your pre-operative information and the report of your earlier operation if you still have them. Their absence does not always prevent surgery, but it must be flagged up.

Examining the retina and setting out your expectations

An examination of the back of the eye and, depending on the case, imaging of the macula look for abnormalities that could compromise the result. A very dense cataract can limit the visibility of the deeper structures: the surgeon will then tell you what uncertainties remain. The final choice has to take account of what the assessment can genuinely evaluate.

Prepare a concrete description of your needs. State how far away your screen is, how much time you spend reading, how often you drive at night and whether you would accept wearing glasses occasionally. Also ask which alternative would be used if the conditions found during the operation did not allow the planned implant to be fitted. This discussion gives consent a proper framework before the day of surgery.

How is a multifocal implant fitted?

Surgery removes the natural lens through a small incision and usually keeps its envelope, known as the capsule, to hold the implant. The lens is fragmented and aspirated; the foldable implant is then introduced and unfolded. Surgery is often carried out as a day case, under local anaesthetic, with arrangements suited to your health and to your ability to stay still.

You may perceive light and certain sensations during the procedure. The team needs to know if you are very anxious, if you have a cough that is hard to control or difficulty lying flat. These points allow the positioning and the anaesthetic to be adapted. They should not be discovered at the last moment in the operating theatre.

When both eyes are concerned, they are treated according to the timetable chosen by the surgeon. There is no universal interval that suits every patient. The result and the tolerance of the first eye can inform what follows, while some situations allow a different arrangement. Your correction between the two operations deserves to be planned ahead if there is a large difference between your eyes.

The implant is designed to stay in place for the long term. It is not removed daily and needs no cleaning by the patient. Eye drops and check-ups relate to healing and to the health of the eye, then to long-term monitoring. Good acuity is not a reason to skip these appointments.

Halos, glare and contrast: the limits to know about

These optical effects come on top of the risks of any lens surgery. Infection inside the eye, marked inflammation, a rise in pressure or a retinal complication can occur. A tear in the capsule during the operation can lead the technique to be adapted, or the planned multifocal implant to be abandoned. Some complications can cause lasting loss of vision. These risks, described by the National Eye Institute and the Société française d’ophtalmologie, must be discussed even when the eye is healthy and the main objective is to reduce the use of glasses.

Halos are rings perceived around light sources, and they are particularly visible in the dark. Glare can be troublesome when facing headlights or intense lighting. Reduced contrast sensitivity sometimes makes it harder to distinguish low-contrast detail, even when reading black letters on a white background in the consulting room remains good.

These phenomena can lessen as your vision adapts, but they are not certain to disappear. Neuroadaptation is no guarantee of tolerance. Significant discomfort should be described precisely: the time of day, the activities affected, the difference between the eyes and how things are changing. The team can then look for a correctable cause instead of systematically putting every symptom down to insufficient time to adapt.

The ESCRS information sets out the possible optical effects and the monofocal or extended depth of focus alternatives. It also points out that the benefit depends on the overall health of the eye. A useful comparison should therefore include night-time comfort and contrast, as well as the number of distances available without glasses.

Finally, an expected optical effect has to be distinguished from a complication. Significant pain, a drop in vision, marked redness or new flashes of light are not simply a matter of adapting to a multifocal implant. These symptoms call for prompt advice, and sometimes urgent advice. Do not let them run on while you wait for a spontaneous improvement.

Recovery and result: how should they be judged?

Vision can improve soon after the operation while still fluctuating. Healing, the ocular surface, transient inflammation and the balance between the two eyes all influence comfort. Tests carried out once things have stabilised help to distinguish a small refractive error from a limitation linked to the implant or to another structure.

Follow the prescription for eye drops and the protection that is recommended. The surgeon will say when to go back to sport, swimming, eye make-up or an activity that exposes you to dust. Avoid rubbing the eye. Driving again depends on your actual vision and on the post-operative check-up; it cannot be deduced from the number of days that have passed.

To judge the benefit, compare identical activities in similar conditions. Reading small text in poor light does not assess the same thing as reading a well-lit phone. An occasional pair of glasses can improve a demanding task without making the operation pointless. The result should be set against the objectives defined before surgery, and against the weight given to each use.

Check-ups are still needed further down the line. The implant offers no protection against retinal disease, glaucoma or a change in the ocular surface. Keep its card or its exact reference and the reports. These documents make it easier to analyse any future loss of vision and to exchange information between professionals, particularly if you move house or are followed up elsewhere.

What if vision remains unsatisfactory?

Persistent discomfort calls first of all for a diagnosis. It may come from dryness, a residual astigmatism, a centring problem, a macular condition or clouding of the capsule. The treatment differs for each cause. A further operation is therefore not decided simply because you still wear glasses.

Posterior capsule opacification, sometimes called a secondary cataract, affects the envelope left behind the implant. It is not the natural lens growing back. When it explains the problem, an opening made with a YAG laser can be offered. However, if exchanging the implant is being considered, that should be discussed before this laser, because the state of the capsule matters for any later surgery.

A correction with glasses, contact lenses or sometimes corneal laser surgery can be discussed for a residual refractive error. In selected situations, repositioning or exchanging the implant may be necessary. An exchange is a genuine second operation, with its own difficulties and risks; it does not make the first choice a trivial one. A specialist opinion can help when several mechanisms are combined.

The price of a multifocal implant and the questions to ask about the quote

The budget is not limited to the price of the lens. It can include the assessment, the operation, the fees, the supplement linked to the model and the check-ups. The terms differ between cataract surgery and lens replacement carried out for refractive reasons. A price per eye should not be compared with an amount covering both eyes without examining these elements.

Ask for a quote that states the planned model, whether it is toric, the correction target and the costs that may remain yours to pay. Have the terms of reimbursement confirmed by your health insurer and your top-up insurance; cover for a cataract does not automatically mean that every implant option is reimbursed. No universal price can describe all of these situations.

If you are comparing several centres, ask how persistent discomfort would be investigated and who would carry out the check-ups. If you travel abroad, plan access to an examination after you return and the transfer of your measurements. A promise of complete independence from glasses is no substitute for these details. The implant that suits you best is the one whose advantages match your priorities and whose limits you understand before surgery.

Sources

1. Société française d’ophtalmologie. (2026). Implants premiums. Fiche d’information 1C.
2. European Society of Cataract and Refractive Surgeons. (n.d.). Chirurgie de la cataracte.
3. de Silva, S. R., Evans, J. R., Kirthi, V., Ziaei, M., & Leyland, M. (2016). Multifocal versus monofocal intraocular lenses after cataract extraction. Cochrane Database of Systematic Reviews, 12, CD003169.
4. National Eye Institute. (2024, December 5). Cataract surgery.
5. Jacob, S. (2022, February 1). Everything you always wanted to know about… Posterior capsular opacification (PCO). EuroTimes, European Society of Cataract and Refractive Surgeons.