Cataracts and night halos: what the EDOF implant changes

Light halos at night are among the main concerns after cataract surgery. Long associated with conventional diffractive multifocal implants, they can now be limited by EDOF (Extended Depth of Focus) implants, a new generation of optics that broadens the depth of field without producing the same nighttime artifacts.

Contents

Cataracte : essayez les trois familles d'implants

Basculez d'un implant à l'autre. Les scènes nettes correspondent aux distances vues sans lunettes ; les scènes floues à un appoint lunettes souvent utile.

Vision nette ou floue selon l'implant et la distance Trois scènes côte à côte représentant la vision de près (un menu), intermédiaire (un écran) et de loin (un panneau de rue). Selon l'implant choisi, chaque scène apparaît nette ou floue. Monofocal : net de loin seulement. EDOF : net de loin et en intermédiaire. Multifocal : net aux trois distances, avec halos possibles la nuit et lecture de près plus confortable avec un bon éclairage. Menu Velouté de saison Filet de bar, beurre blanc Tarte fine aux pommes 12249 Près lecture, ~30 cm net sans lunettes lunettes utiles Intermédiaire écran, ~60 cm net sans lunettes lunettes utiles RUE DE L'ÉGLISE Loin conduite, panneaux net sans lunettes lunettes utiles Schéma pédagogique. Le rendu réel dépend de chaque œil.

Multifocal : des halos peuvent être perçus la nuit en vision de loin ; la lecture de près est plus confortable avec un bon éclairage.

Le choix de l'implant dépend de votre œil et de votre mode de vie ; il se décide avec le chirurgien.

Net sans lunettes Appoint lunettes souvent utile

UNDERSTANDING

Understanding night halos after cataracts

Light halos are an example of positive dysphotopsia: the perception of concentric rings around bright light sources (car headlights, illuminated signs, street lamps). Their origin is optical: the intraocular implant diffracts light into several focal points to restore vision at different distances. This distribution of light energy can generate artifacts, particularly visible at night when the pupil is dilated.

According to Corbett et al. (Eye, 2024), non-diffractive EDOF implants cause noticeably fewer halos and glare at night than previous-generation multifocal implants, for a large majority of patients, while offering an extended range of sharp vision. In practical terms, this means more comfortable night driving: reflections around headlights and illuminated signs are reduced, and reading the GPS or the dashboard remains pleasant. The experience nonetheless varies depending on pupil profiles and visual habits.

The intensity of the light halo after cataract surgery depends above all on the type of implant chosen. This phenomenon is mainly linked to multifocal implants, and trifocals in particular, whose optics distribute light across several focal points; the latest-generation models have markedly reduced it. With an EDOF implant, halos are far more discreet, and they are almost absent with a monofocal implant, which does not split the light — at the cost, however, of a correction limited to a single distance. In a person affected by cataracts, the clouded lens scatters light and heightens light sensitivity as well as the halos perceived around lights ; replacing it with a clear artificial lens most often restores normal everyday activities and reduces the wearing of glasses.

WHO IS AFFECTED

Who is affected by these halos?

Night halos primarily affect certain situations:

  • Night drivers (professionals, long journeys)
  • Night-time or shift-work occupations
  • Artists, photographers, screen workers in low light
  • Patients fitted with older-generation diffractive multifocal optics
  • Patients with large scotopic pupils (> 5 mm in low light)

A preoperative questionnaire on visual habits together with an examination of pupil dynamics helps identify the highest-risk profiles and guide the choice of implant accordingly.

SOLUTIONS

The solutions: the EDOF implant

EDOF (Extended Depth of Focus) implants extend the depth of field rather than creating several distinct focal points. Two main technologies exist:

  • Vivity (Alcon): a non-diffractive EDOF using wavefront-shaping technology. Its modified optical profile extends the depth of field while strongly limiting night halos, close to those of a monofocal implant. Continuous vision from far to intermediate, with glasses often useful for fine reading.
  • Pure See (Johnson & Johnson, TECNIS PureSee™ range): a latest-generation refractive EDOF. It offers an extended range of vision from far to intermediate, with a halo profile very close to that of a standard monofocal implant: an asset for night drivers and screen workers.
  • Earlier diffractive EDOF (Symfony, TECNIS Eyhance): improved intermediate vision with a diffractive profile optimized to limit halos compared with conventional trifocals.

A study published by Georgiev et al. (JCRS, 2020) involving patients switched to a bilateral toric EDOF implant showed a clear reduction in bothersome halos and glare, high patient satisfaction and a more occasional need for glasses at far and intermediate distances. It remains important to remember that EDOF does not fully replace fine reading: patients who are very demanding about reading small print may need glasses for small characters.

To learn more about the available techniques and implants, see the cataract surgery page or the details of premium implants.

PATHWAY

The care pathway

Dr Tourabaly sees patients at the Cachan (94) practice and in Paris 13 for the preoperative cataract assessment. The work-up includes optical biometry (IOL Master), corneal topography, a macular OCT and an examination of pupil dynamics. These examinations determine the choice between a monofocal implant, an EDOF or a multifocal.

Surgery is performed at the Clinique Sainte-Geneviève (Paris 14), in a dedicated operating facility. The two eyes are operated 2 to 4 weeks apart depending on visual stability. To make an appointment, call the practice at 01 45 47 08 11 or via Doctolib.

Dr Tourabaly’s view

“An EDOF implant is not indicated for every patient. For those who drive a lot at night, I generally prefer to offer a non-diffractive EDOF rather than a multifocal. Conversely, for someone whose main goal is complete independence from glasses and who tolerates halos well, the trifocal remains a suitable option. The time devoted to this discussion before surgery greatly changes the perceived outcome.”

FAQ

Frequently asked questions

An EDOF (Extended Depth of Focus) implant extends the optical depth of field rather than creating several distinct focal points. It restores continuous far and intermediate vision with fewer night-time light artifacts than a conventional diffractive multifocal.

The trifocal restores three distances (far, intermediate, near) at the cost of more pronounced night halos. The EDOF favours far and intermediate vision with fewer halos, but often requires glasses for fine reading. The choice depends on visual priorities and the patient’s profile.

For far and intermediate vision (computer screen, car interior), most patients become independent of glasses. For fine reading (paperback books, instruction leaflets), glasses may remain useful, especially in low light. A preoperative discussion helps calibrate expectations.

The cataract surgical procedure is reimbursed by the French health insurance (Sécurité sociale). Standard monofocal implants are fully covered. Premium implants (EDOF, multifocal, toric) involve a non-reimbursed additional fee, partly covered by some complementary health insurers (mutuelles).

Night driving is generally well tolerated with an EDOF, particularly a non-diffractive one, which limits halos compared with conventional multifocal implants. The first few weeks may involve moderate halos during neuroadaptation, often reduced within 1 to 3 months. It is advisable to resume night driving gradually after medical advice.

The Vivity (Alcon) is a non-diffractive EDOF implant that uses a technology known as wavefront-shaping: instead of splitting light into several focal points, it stretches the focal point to broaden the depth of field. The result: continuous vision from far to intermediate, with a halo profile close to that of a monofocal implant: particularly suited to patients sensitive to night-time glare.

The Pure See (Johnson & Johnson, TECNIS PureSee™ range) is a latest-generation refractive EDOF implant. It restores an extended range of vision from far to intermediate, while keeping a halo profile very close to a monofocal implant. It is a suitable option for patients who wish to limit their dependence on glasses for everyday life without experiencing the halos of conventional trifocal multifocals.

Discuss your implant choice with Dr Tourabaly

Book an appointment on Doctolib
Learn more: cataract surgery

Sources

  1. Corbett D, Black D, Roberts TV, et al. Quality of vision clinical outcomes for a new fully-refractive extended depth of focus intraocular lens. Eye (Lond). 2024;38(10):1815-1820. PMID 38580741
  2. Georgiev S, Palkovits S, Hirnschall N, et al. Visual performance after bilateral toric extended depth-of-focus IOL exchange. J Cataract Refract Surg. 2020;46(12):1624-1629. PMID 33060471

This article is for informational purposes. A personalized ophthalmological opinion remains essential for any treatment decision.

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Written and reviewed by Dr Moïse Tourabaly, ophthalmic refractive surgeon — former chief resident (Quinze-Vingts National Eye Hospital).

Last updated: July 6, 2026

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