Trifocal or EDOF Lens? Choosing Your Smart Lens
How two popular smart lenses work, what the research says, and which one may suit your profession and lifestyle better.
Both are successful smart lenses. The difference is the distance at which each one is strongest. A trifocal lens is the strongest option for near vision (about 40 cm). Therefore it suits people who work with books, phones and fine near tasks. However, you may see halos around lights at night. An EDOF lens gives continuous, high-quality distance and intermediate vision, and night halos are less common. Near reading, though, may stay more limited. Your eye structure, your profession and your expectations decide the right choice.
How does a trifocal lens work?
The surface of a trifocal lens has fine rings that split light by diffraction. These rings divide incoming light into three focal points: distance, intermediate (about 55–60 cm, computer) and near (about 40–45 cm, book and phone). As a result, most patients do not need glasses in daily life.
However, there is a trade-off, because the light is split. Contrast may decrease a little, and you may see rings (halos) around headlights or street lamps at night. Over time, the brain adapts to this new way of seeing. In one functional MRI study, this adaptation (neuroadaptation) needed intense attention in the first weeks. Then brain activity returned to normal at 6 months.
“For people who use computers, work as accountants, love reading books and newspapers, or do intensive close work, no other lens gives the near vision that trifocal lenses give. If there is a need for near vision, I still think trifocal lenses are number one.”
— Prof. Dr. Fırat Helvacıoğlu, from his video talk
Smart lens choice: are trifocal lenses dead?
Prof. Dr. Fırat Helvacıoğlu explains how EDOF lenses have developed and in which patients he still sees trifocal lenses as the first choice.
How does an EDOF lens work?
EDOF (extended depth of focus) lenses do not split light into separate focal points. Instead, they stretch the focus along a line. Their distance vision quality is very close to that of a single-focus (monofocal) lens. Also, they give continuous vision from about 50–60 cm onward. Because they have no distinct rings, night halos and glare are less common.
Older EDOF lenses were not strong enough for near vision. New-generation models have clearly improved it. Still, they are not as strong as a trifocal for small print and for distances under 40 cm. To close this gap, we can plan mini-monovision, which sets one of the two eyes slightly for near. New “hybrid” lenses that combine the strengths of trifocal and EDOF lenses are also among the options. For details, see our EDOF lens page.
Trifocal and EDOF lens: structure and viewing distances
A trifocal lens splits light into three focal points with rings on its surface, while an EDOF lens stretches the focus along a line. The graphic shows the sharpness profile of the two lenses by distance, as a representation.
- Trifocal lensThree focal points for distance, intermediate (computer) and near (reading). The strongest option for near vision; halos may appear around lights at night.
- EDOF lensContinuous sharpness from distance to arm's length. Near reading may be more limited; night halos and glare are less common.
- Focus curveThe trifocal makes a second peak at 40 cm. The EDOF offers wide sharpness at distance and intermediate, and lower sharpness up close.
What does research say about a trifocal or EDOF lens?
- A meta-analysis comparing trifocal and EDOF lenses found similar distance vision in both groups. EDOF was better at intermediate distance, and trifocal was better up close. The rate of becoming completely glasses-free was higher in the trifocal group. Patient satisfaction was high with both lenses.
- Another meta-analysis reported that trifocal lenses were superior for near vision. However, complaints of halos were more frequent in the trifocal group.
- A network meta-analysis combining 27 randomized studies concluded that trifocal lenses in both eyes may give the best near vision without compromising distance vision.
- According to the Cochrane review, glasses independence with multifocal lenses is clearly higher than with single-focus lenses. On the other hand, halos and glare are more frequent.
So the scientific data also say this: both lenses are good, but they serve different needs.
Who suits which: a trifocal or EDOF lens?
Good candidate for a trifocal
- People who read many books and newspapers and hold the phone close
- Accountants, tailors, barbers and others who do fine close work
- People who want to be as glasses-free as possible
- Farsighted people over 45 who see neither near nor far well
Good candidate for an EDOF
- People who drive a lot at night, professional drivers and pilots
- People who put distance vision quality and contrast first
- People who work mostly at the computer and at intermediate distance
- People who know they are sensitive to halos around lights
You cannot make this decision just by reading a lens brochure. Before surgery, we evaluate your cornea, astigmatism, macula and optic nerve with detailed measurements. Then we discuss together where you use your eyes most in your life.
Situations that need attention
- Macular disease, advanced glaucoma or an irregular cornea: Lenses that split light can lower vision quality in these eyes. Therefore a single-focus (monofocal) lens is usually preferred.
- Astigmatism: Both trifocal and EDOF lenses have toric models that correct astigmatism. For the calculation, we use the astigmatism of the cornea, not the one in your glasses.
- Nearsighted people around age 50: Nearsighted patients who see very well up close without glasses may lose this advantage at distances like 20 cm after surgery, whichever lens we implant. Setting the right expectation is very important in this group.
- Eyes that had laser before: We use special formulas to calculate the lens power. A regular cornea and a centered laser treatment are important.
- If a small refractive error remains: With modern measurements it is rare. Even so, a small error can bother you with multifocal lenses. In this case, surface laser (PRK) can fine-tune the result.
“There is no perfect lens and no single perfect treatment. Our aim is to give you vision as close as possible to your healthy 20-year-old eye. For this, we need to set expectations according to real results.”
— Prof. Dr. Fırat Helvacıoğlu, from his smart lens interview
Our clinic's studies
Smart lenses have been an important part of our practice for many years. We share our clinical results in this field at international congresses. These include studies on postoperative visual performance with bifocal and trifocal diffractive lenses (ESCRS 2019), corneal (topographic) factors affecting dissatisfaction after a trifocal lens (ESCRS 2018) and fine-tuning with PRK after a multifocal lens (ESCRS 2018).
For information about smart lens surgery done only to get rid of glasses, without cataract, see our smart lens and presbyopia treatment pages. In cataract surgery in Turkey, the standard lens covered by the state insurance (SGK) is the monofocal lens. If you choose a smart lens, the patient pays the lens price difference.
Frequently asked questions
Yes, the great majority of patients can drive at night. In the first months, you may see rings around headlights. The brain usually adapts to this within 6 months. If you drive at night for very long periods, an EDOF lens may be more suitable.
With new-generation EDOF lenses, most patients can read the phone and normal-size print. For very small print and long near reading, however, you may sometimes need thin reading glasses. Mini-monovision planning can reduce this need.
In most patients they decrease clearly over time. This adaptation process is called neuroadaptation, and it usually finishes within 6 months. In a few patients the complaint may continue. In this case, we evaluate the eye and, if needed, apply additional solutions.
Yes. Lenses placed inside the eye are made to last for life without deteriorating, and you never get a cataract again. If the capsule behind the lens becomes cloudy over the years, a short YAG laser procedure clears it.
It can be replaced if needed. However, it is not a surgery done because “a new model came out”. In cases such as intolerable vision complaints or a clear refractive shift, we do it carefully while preserving the capsule.
Related pages
References
- Guo Y, Wang Y, Hao R, Jiang X, Liu Z, Li X. Comparison of patient outcomes following implantation of trifocal and extended depth of focus intraocular lenses: a systematic review and meta-analysis. J Ophthalmol. 2021;2021:1115076. doi:10.1155/2021/1115076
- Zhong Y, Wang K, Yu X, Liu X, Yao K. Comparison of trifocal or hybrid multifocal-extended depth of focus intraocular lenses: a systematic review and meta-analysis. Sci Rep. 2021;11(1):6699. doi:10.1038/s41598-021-86222-1
- Cho JY, Won YK, Park J, et al. Visual outcomes and optical quality of accommodative, multifocal, extended depth-of-focus, and monofocal intraocular lenses in presbyopia-correcting cataract surgery: a systematic review and Bayesian network meta-analysis. JAMA Ophthalmol. 2022;140(11):1045-1053. doi:10.1001/jamaophthalmol.2022.3667
- de Silva SR, Evans JR, Kirthi V, Ziaei M, Leyland M. Multifocal versus monofocal intraocular lenses after cataract extraction. Cochrane Database Syst Rev. 2016;12:CD003169. doi:10.1002/14651858.CD003169.pub4
- Rosa AM, Miranda ÂC, Patrício MM, et al. Functional magnetic resonance imaging to assess neuroadaptation to multifocal intraocular lenses. J Cataract Refract Surg. 2017;43(10):1287-1296. doi:10.1016/j.jcrs.2017.07.031
- Helvacıoğlu F, Sunay E, Kaya Ünsal S, Kavalcıoğlu Ö, Bulut E. Postoperative visual performance with a bifocal and trifocal diffractive intraocular lens. 37th ESCRS Congress, Paris, September 2019 (paper).
- Kaya Ünsal S, Helvacıoğlu F, Sunay E. Topographic factors affecting dissatisfaction after trifocal IOL implantation. 36th ESCRS Congress, Vienna, September 2018 (paper).
- Helvacıoğlu F, Sunay E, Kaya Ünsal S, Kavalcıoğlu Ö, Akyurt A, Akın T. PRK fine tuning after multifocal IOL implantation. 36th ESCRS Congress, Vienna, September 2018 (paper).
This article is for patient information only and does not replace an examination and medical evaluation. The treatment that suits you is decided after an eye examination and measurements. Publication date: 25 September 2026.
Contact Prof. Dr. Fırat Helvacıoğlu with your questions
Prof. Dr. Fırat Helvacıoğlu · Veni Vidi Eye Clinic, Bağdat Cad. No: 257, Caddebostan – Kadıköy / Istanbul