Trifocal Lens (Multifocal Intraocular Lens)

Objective information about the trifocal intraocular lens — suitability is assessed with the examination and measurements of Dr. Nejmi Öztürk, ophthalmologist and eye surgeon, at HG Hospital in Kahramanmaraş, Türkiye

What is a trifocal lens?

A trifocal (three-focus) lens is a multifocal intraocular lens placed inside the eye that aims to give clear vision at distance, intermediate and near at the same time. In Turkish it is popularly called “akıllı lens”, meaning “smart lens”, but the lens does not “think” or change focus; fine rings on its surface split incoming light into three separate focal points. The brain learns to select the image that is sharp for the distance being viewed. This is why medical texts use the terms “trifocal”, “multifocal” or “presbyopia-correcting lens”.

A trifocal lens is placed in the same position as the lens used in cataract surgery, that is, inside the capsular bag that remains after the natural lens is removed. It is permanent, needs no daily care and is not visible from the outside. The three focal distances are designed approximately for distance (driving, television), intermediate (computer, kitchen counter, 60–80 cm) and near (reading, phone, 40 cm).

In which situations is a trifocal lens implanted?

A trifocal lens is implanted for two purposes: chosen to replace the cloudy lens in cataract surgery, or in a person without a cataract, by replacing the clear lens solely to be free of glasses (refractive lens exchange). When implanted together with cataract surgery, it both removes the cloudiness and greatly reduces the need for distance and reading glasses. In refractive lens exchange, the aim is to correct together the presbyopia (age-related difficulty seeing up close) that appears after 45 and any distance prescription.

Who is a trifocal lens suitable for?

A trifocal lens is suitable for people over 40–45 with healthy eyes who want to reduce their dependence on glasses. The main criteria for suitability are:

• Patients scheduled for cataract surgery who do not want distance and reading glasses
• People over 45 who have recently started using reading glasses or who use both distance and reading glasses
• People whose retina, macula and optic nerve are healthy
• People with a regular cornea; in those with regular astigmatism a toric trifocal lens can be used
• People, particularly those with high hyperopia, whose prescription or corneal thickness is not suitable for laser eye surgery
• People with realistic expectations who accept night halos and an adaptation period lasting weeks

Who is it not suitable for?

A trifocal lens is not suitable for people whose retina or cornea is not healthy, because the lens splits light, and in eyes whose visual quality is already reduced the result is inadequate. The main situations are:

• Diseases of the macula such as macular degeneration, diabetic macular edema and epiretinal membrane
• Advanced glaucoma (high eye pressure) that has caused visual field loss
• Irregular corneal structures such as keratoconus, corneal scarring or previous radial keratotomy
• Advanced dry eye that cannot be brought under control despite treatment
• A pupil that is very large, very small or irregular; weakness of the fibers that hold the lens
• Eyes with amblyopia (lazy eye) (the lens cannot raise vision above the level of the amblyopia)
• People who drive at night for a living and have a low tolerance for halos; in this group the decision is made with care, and an EDOF or monofocal lens is usually preferred

Being on this list does not mean that a trifocal lens can never be used for you; the decision is determined by the examination and measurement results. In patients who are not suitable, if a cataract is present, cataract surgery with a monofocal or toric lens can be performed.

Will I be completely free of glasses after a trifocal lens?

The great majority of patients with a trifocal lens do not use glasses in daily life; however, glasses may occasionally be needed for very small print, prolonged reading in dim light or fine handwork. The right expectation is therefore “a large reduction in dependence on glasses”. If a small prescription remains after surgery, it can be fine-tuned with glasses or, if the cornea is suitable, with laser.

Seeing halos and glare around light sources at night is a known effect that arises from the structure of the trifocal lens. In most patients this effect decreases within weeks to months as the brain adapts to the new image (neuroadaptation). Contrast sensitivity (the ability to distinguish shades) in dim light is slightly lower than with a monofocal lens. Having both eyes operated on with a trifocal lens, close together in time, makes adaptation easier.

Which examinations and tests are done before surgery?

The decision on a trifocal lens is made with measurements of the cornea, macula, dry eye and pupil in addition to the standard cataract examination, because the result of this lens depends on the health of the rest of the eye.

• Optical biometry: The length of the eye and the curvature of the cornea are measured; the lens power is calculated. The target is a post-operative prescription close to zero.
• Corneal topography: The amount of astigmatism and whether it is regular are determined; whether a toric trifocal lens is needed is decided. If an irregular cornea is found, a trifocal lens is not recommended.
• OCT (optical coherence tomography of the eye): The layers of the macula are examined; early macular diseases that are not otherwise visible are revealed by this measurement.
• Dry eye assessment: The tear film is examined; if there is significant dryness, it is treated first, otherwise the measurements will be misleading and the result will remain blurred.
• Pupil measurement: The pupil diameter in dim light is measured; a very large pupil can increase night halos.
• Fundus examination: The retina and optic nerve are assessed with the pupil dilated.

At the examination you will be asked in detail about your daily life, your occupation, whether you drive at night and what you expect regarding glasses. This information is as decisive in the choice of lens as the measurements.

How is trifocal lens surgery performed?

Trifocal lens surgery is technically the same as cataract surgery: it is done with anesthetic drops, through an incision of about 2–3 mm, using the phacoemulsification method (breaking up the lens with ultrasound), in 15–30 minutes. The difference is that the lens implanted is trifocal.

1. Drops that dilate the pupil and numb the eye are applied; the area around the eye is cleaned with an antiseptic solution.
2. A small incision is made at the edge of the cornea; a neat, round opening is created in the front surface of the membrane that surrounds the lens. The regularity of this opening is important for centering the trifocal lens.
3. The natural lens is broken up with ultrasound energy and removed by suction; the back membrane is left in place.
4. The foldable trifocal lens is delivered with an injector, unfolds in the capsular bag and is centered on the pupil. If a toric trifocal lens is used, it is rotated to the axis calculated beforehand.
5. The incision is checked for leaks; a protective shield is placed over the eye. Stitches are usually not needed.

During the procedure you feel light, mild pressure and touch; afterwards there may be stinging and watering for a few hours. You go home the same day. The two eyes are usually operated on between a few days and two weeks apart; with multifocal lenses, doing the two eyes close together makes the brain’s adaptation easier. Because you cannot drive after the surgery, you need to come with a companion.

Trifocal lens surgery step by step

Removal of the natural lens and placement of a trifocal lens, shown schematically on a cross-section of the front of the eye.

1. Removing the natural lensThe natural lens is broken up with ultrasound energy and removed by suction through a small incision; the capsular bag is preserved.
2. Placing the trifocal lensThe trifocal lens is inserted in folded form, unfolds inside the capsular bag and stays centred.
3. Three focal pointsThe lens distributes incoming light to far, intermediate and near focal points. It may take a few weeks for the brain to adapt to this image.

What are recovery and adaptation like?

Distance vision clears from day 1 in most patients; near and intermediate vision settle over weeks, because it takes time for the brain to learn to use the three focal points.

• Day 1: The protective shield is removed; eye pressure and the centering of the lens are checked. Antibiotic and anti-inflammatory drops are started. Vision may be hazy; night halos are noticeable during this period.
• Week 1: Do not rub the eye, keep water out of it and do not lift heavy objects. Reading and screen use are allowed. You can return to desk work within a few days.
• Month 1: The drops are tapered and stopped. You wait a month before swimming pools, the sea and the hammam (Turkish bath). Visual acuity and any remaining prescription are measured; if the other eye has not yet been done, it is planned.
• Month 3: Neuroadaptation is assessed; whether the halos have decreased, the level of near vision and, if necessary, the need for fine-tuning are discussed.

If you are coming from Elbistan, Afşin, Göksun, Ekinözü or Nurhak, the day of surgery and the day 1 check-up are planned together; the week 1 and month 1 check-ups are arranged according to your travel conditions.

What are the risks and limitations of a trifocal lens?

The risks of trifocal lens surgery are the same as those of cataract surgery; in addition, there are visual side effects arising from the optical structure of the lens.

• Halos and glare: Halos, starburst-like scattering and glare around lights at night; they usually decrease within months and may be permanent in a small number of patients.
• Reduced contrast: The ability to distinguish shades in dim light and fog is slightly lower than with a monofocal lens.
• Need for glasses for small print: Glasses may be needed for very small print and for reading in dim light.
• Residual prescription: Despite the measurements, a small prescription may remain; a trifocal lens is more sensitive to this than a monofocal lens. Fine-tuning with glasses or laser may be needed.
• Failure to adapt: Rarely, a patient cannot adapt to the halos or the image quality even after months; in that case, exchanging the lens for a monofocal lens may be considered. This is a second operation and can be more difficult depending on the condition of the capsular bag.
• Posterior capsule opacification: Clouding of the membrane the lens sits in affects visual quality earlier with trifocal lenses; it is cleared with a YAG laser.
• General surgical risks: Infection, macular edema, a rise in eye pressure and retinal detachment (particularly in highly myopic people) are rare but possible.

As a limitation, no trifocal lens exactly reproduces the natural focusing of a young eye. It reduces dependence on glasses and offers easy transition between distances in exchange for small compromises in visual quality. For patients who do not accept this trade-off, a monofocal or EDOF lens may be more suitable.

What are the alternatives to a trifocal lens?

The alternatives to a trifocal lens are the EDOF lens, the monofocal lens (with monovision if desired) and, in younger patients, ICL, which preserves your own lens, and laser treatments. The table below summarizes the main differences.

Option	Distance	Intermediate	Near	Night halos	Who it is for
Trifocal (multifocal)	Clear	Clear	Clear	Moderate; decreases over time	People over 45 with healthy eyes who want to be largely free of glasses
EDOF	Clear	Clear	Sufficient for large print; glasses for small print	Low–moderate	People who drive at night or prioritize computer distance
Monofocal / toric	Clear	Limited	With glasses	Low	People with additional eye disease or who want the simplest image
ICL (phakic lens)	Clear	With your own lens	With your own lens	Low	Ages 21–45, high myopia, no cataract
Laser eye surgery	Clear	With your own lens	Glasses after 45	Low	Younger people with a suitable cornea and a prescription within the limits

A general comparison of all lens types is on the lens surgery page.

Assessment and planning in Kahramanmaraş

Your suitability for a trifocal lens is assessed with the examination and measurements at HG Hospital in Kahramanmaraş, Türkiye; the method that suits you is planned together. The examination is done by Dr. Nejmi Öztürk, an ophthalmologist working in cataract and refractive surgery. If you have a cataract, cataract surgery is performed by Dr. Öztürk at HG Hospital; the decision on the lens type, including a trifocal lens, is made together according to the measurement results and your expectations.

Is a trifocal lens covered by SGK or insurance?

HG Hospital is a private hospital contracted with the Turkish social security institution (SGK); patients with valid SGK coverage may use it, although a private-hospital co-payment may apply. For these patients, cataract surgery with a standard monofocal lens is covered; if a trifocal lens is chosen, the lens surcharge is paid by the patient. Lens exchange done solely to be free of glasses in a person without a cataract is generally not covered by SGK. Patients without SGK coverage, such as international patients and visitors from abroad, pay privately or through their private or travel health insurance; the hospital checks coverage before treatment. Coverage conditions and fee information are clarified by the hospital after the examination.

Dr. Öztürk does not see patients in Elbistan; patients from Elbistan, Afşin, Göksun, Ekinözü and Nurhak come to HG Hospital in Kahramanmaraş. The examination and all measurements are completed on the same day; travel and planning information is on the patients from Elbistan and the surrounding area page.

Frequently asked questions

Sources

• Turkish Ophthalmological Society — todnet.org
• American Academy of Ophthalmology (AAO) — aao.org
• European Society of Cataract and Refractive Surgeons (ESCRS) — escrs.org
• National Eye Institute (NEI) — nei.nih.gov

Related pages

• EDOF (extended depth of focus) lens
• Cataract surgery (monofocal and toric lens)
• Lens surgery — all options
• ICL (phakic intraocular lens) surgery

This page is for information only; diagnosis and treatment decisions are made after an examination. The results of any surgical or interventional procedure may vary from person to person. You are advised to obtain detailed advice from your physician before any procedure.