Cataract surgery involves replacing the eye’s cloudy lens with a synthetic intraocular lens (IOL) to restore clear vision. One of the choices available to patients is a multifocal IOL, designed to offer different levels of vision correction, allowing clear vision at various distances. This lens is also available to patients who do not have cataracts but are interested in lens replacement surgery (refractive lens exchange) to correct vision problems.
What Is a Multifocal IOL?
A multifocal lens is an artificial intraocular lens (IOL) designed to provide focus for both near and distance vision. Unlike standard monofocal lenses, which only correct for a single type of vision, multifocal lenses have multiple focal points, allowing patients to see clearly at multiple distances without glasses or contact lenses. They are typically used in cataract surgery to restore the refractive properties of the lens after its removal.
How Does a Multifocal IOL Work?
Multifocal IOLs use different optical powers across the lens. Manufacturers etch concentric rings on the surface of the lens. These rings are designed to focus light from different distances onto the retina. Eye muscles pull on the lens when you need to focus, allowing you to see both near and distant objects more clearly.
Monofocal vs Multifocal IOL
The choice between a basic monofocal or multifocal IOLs depends on your visual needs, lifestyle, and willingness to accept potential visual trade-offs. Here’s a list of what each lens can do for you and the most relevant facts about them:
Monofocal IOLs:
- Provide clear vision at a single distance, usually for distance vision
- Patients will likely need glasses for near or intermediate vision
- Considered the standard or traditional IOL option for cataract surgery
- Generally less expensive than multifocal IOLs, often covered by insurance
Multifocal IOLs:
- Provide clear vision at multiple distances – near, intermediate, and far
- Aim to reduce or eliminate the need for glasses after cataract surgery
- More expensive than monofocal IOLs, often not fully covered by insurance
- May have a higher risk of visual side effects like glare, halos, and reduced contrast sensitivity compared to monofocal IOLs, although the risk is very low.
- Newer multifocal lens designs have improved on these visual side effects compared to older models.
Accommodating vs Multifocal IOL
Accommodating IOLs are a different type of IOL designed to restore the eye’s natural ability to focus on objects at varying distances. Unlike multifocal IOLs, accommodating IOLs are designed to move within the eye to change focus distances, mimicking the natural accommodation process of the eye. These lenses are an effective treatment for presbyopia, significantly reducing the need for reading glasses.
If you are interested in having a fuller range of vision without having to use glasses after surgery, both multifocal and accommodating lenses could be a viable option. You should discuss your case with your surgeon, who may recommend one or the other depending on your visual and lifestyle needs.
Multifocal IOL vs EDOF IOL
There is another type of premium IOL that provides an extended range of clear vision: the extended depth of focus or “EDOF” intraocular lens. EDOF lenses are sometimes referred to as “multifocal” lenses, but the two types work in different ways.
EDOF lenses have one focal point (like monofocals) but they incorporate special light-shaping technology to stretch the total range of this focus. This way, they provide good vision from near to distance. The transition between ranges is more seamless, as it all occurs within the same focal area. The downside is some loss of contrast sensitivity and the need for reading glasses in dim light conditions.
Multifocal IOL Options
The first multifocal IOLs offered only two focal points for distance and near vision. Popular models included the Tecnis Multifocal, the AcrySof ReSTOR and the ReZoom IOL. While these lenses offer good vision outcomes, the have been now outperformed by trifocal IOLs, which provide clear vision at near, intermediate and distance ranges.
In the United States, the only trifocal IOL commercially available is the PanOptix trifocal IOL by Alcon. This lens represents one of the best options in vision correction for cataract surgery.
Multifocal Toric Lens
Regular IOLs (whether basic or premium) do not correct astigmatism. But most IOL models have an astigmatism-correcting version called a toric IOL. The term “toric” refers to the special shape of the lens, which corrects the uneven curvature of the eye that causes astigmatism. The Trifocal IOL has a toric version, so patients with astigmatism who want a multifocal lens can obtain their desired vision correction.
Pros & Cons: Are Multifocal IOLs Worth It?
Multifocal lenses are a great option for patients who desire more spectacle independence after cataract surgery, but they are not the only lens with this feature. Depending on your health, vision needs and lifestyle preferences, other lenses might be preferable.
A big factor to consider before your surgery is cost. Multifocal lenses are not covered by insurance, and represent a significant investment. However, the results are worth it for many patients, and financing options make it easier to afford.
The board-certified surgeons at Eye Associates of South Texas have performed hundreds of procedures. Your journey to better vision starts here. Call (830) 379-3937 to schedule a consultation with one of our cataract specialists. Source: nvisioncenters.com.
