The choice of lens implant is the most consequential decision you will make before cataract surgery. A monofocal lens gives excellent vision at one distance with the lowest risk of optical side effects. A multifocal lens offers a wider range of useful vision but involves trade-offs — most notably halos around lights. The best lens is the one matched to your lifestyle, visual priorities, and eye health, not the most technologically advanced option available.
What Is a Monofocal IOL?
A monofocal intraocular lens provides a single focal point — the lens is set to optimise vision at one distance, most commonly far distance. After surgery with a monofocal lens, most patients can drive, watch television, and perform everyday activities without distance glasses. Reading glasses are required for near tasks: reading, using a smartphone, checking a menu.
The key advantages of a monofocal lens are its outstanding optical quality and minimal risk of unwanted visual side effects. Because all of the incoming light is directed to a single focal point, contrast is excellent and the risk of halos, glare, or starbursts around lights is very low. For patients who are happy to use reading glasses and prioritise the best possible distance vision quality, a monofocal is an excellent choice.
A technique called monovision — setting one eye for distance and the other for near — can be used with monofocal lenses to reduce overall glasses dependence, but it requires careful patient selection and a trial to confirm tolerance.
What Is a Multifocal IOL?
Multifocal lenses are designed to provide useful vision at multiple distances simultaneously — typically far, intermediate, and near — by splitting incoming light into separate focal points. The brain learns to use the appropriate focal point for the task at hand. For motivated patients with good eye health, multifocal lenses can dramatically reduce or eliminate the need for both distance and reading glasses.
The trade-off is dysphotopsia — unwanted optical effects including halos, starbursts, or glare around lights, particularly at night. The prevalence and severity of these effects varies between patients and between lens designs. For most patients, these effects diminish significantly over the first 6 to 12 months as the brain neurally adapts. However, for some patients — particularly those who drive frequently at night or who are very sensitive to light disturbances — these effects remain bothersome.
Multifocal lenses are best suited to patients with excellent overall eye health (particularly a healthy macula and cornea), a genuine desire to reduce glasses dependence across multiple distances, and realistic expectations about the adaptation process. They are not recommended for patients with significant macular disease, irregular corneas, or those with demanding requirements for optical perfection at night.
What Is an EDOF IOL?
Extended Depth of Focus (EDOF) lenses occupy a carefully designed middle ground. Rather than creating separate focal points like a multifocal, they extend the range of clear focus across a continuous zone — from distance through to intermediate (roughly arm's length). The result is excellent distance vision and good intermediate vision (computer screen, car dashboard, cooking), with a more modest improvement in near vision compared to a full multifocal.
The clinical advantage of EDOF lenses over multifocals is a significantly improved halos and glare profile. Because incoming light is not split into multiple focal points simultaneously, contrast sensitivity is better preserved and optical disturbances are less pronounced. The TECNIS PureSee — one of the newest EDOF lenses available — was FDA-approved in March 2026 and is specifically designed to achieve monofocal-equivalent contrast sensitivity while delivering an extended range of vision.
EDOF lenses suit patients who want to reduce their dependence on glasses — particularly for computer and intermediate tasks — without accepting the halos and glare trade-off of a traditional multifocal. Most patients will still occasionally use reading glasses for very fine print or sustained near tasks.
What About Toric Lenses?
Astigmatism is a common refractive error caused by the uneven curvature of the cornea. Standard monofocal lenses do not correct pre-existing corneal astigmatism, meaning patients with significant astigmatism may still need distance glasses after surgery even with a well-powered lens. Toric IOLs — available in monofocal, EDOF, and multifocal designs — incorporate cylindrical correction to neutralise the astigmatism. For patients with moderate to high corneal astigmatism, a toric lens significantly improves uncorrected distance vision.
Cost Differences
A standard monofocal IOL is covered within the Prostheses List, meaning there is no additional out-of-pocket charge for the lens itself beyond the surgical and hospital fees that apply to all patients. Premium lens implants — toric, multifocal, and EDOF designs — involve an additional patient-paid lens fee that is not covered by Medicare or private health insurance. This fee varies by lens type and can range from several hundred to over a thousand dollars per eye. Your surgeon will outline the expected lens cost as part of your pre-operative fee estimate.
How to Choose
The single most important factor in choosing a lens is an honest assessment of your visual priorities and lifestyle. Ask yourself: how important is it to read without glasses? Do you drive at night frequently? Do you spend significant time at a computer? Are you particularly sensitive to visual disturbances? What is your tolerance for reading glasses?
Your surgeon will also assess your suitability for premium lenses based on the health of your retina, cornea, and overall eye. Co-existing eye conditions can limit the benefit of premium designs. The right lens is the one that matches your lifestyle and your eye — not the most expensive option, nor the most conservative. At Northern Eye Consultants, lens selection is a detailed, personalised conversation at your pre-operative consultation.