A wide range of replacement lenses are available to cataract patients, each offering different advantages for post-surgery vision. The most effective lens to use depends on the patient’s individual preferences and goals for their vision. The lenses can reduce dependency on glasses or contacts after cataract surgery, providing most patients with convenient, effective results for their specific vision needs.
It is important to note that all classes of intraocular lenses (IOL’s) can have drawbacks, which is why there is no one “perfect” lens for everyone. Your doctor will discuss the lens options that are likely to work best for you.
Monofocal IOLs (Default Lens)
In the past, cataract surgery only involved monofocal lenses, which could only focus on objects near or far, but not both, since a monofocal lens cannot adjust to accommodate varying distances. These patients still had to rely on glasses or contact lenses after surgery in order to see clearly at all distances.
A monofocal IOL can correct for myopia (nearsightedness) and hyperopia (farsightedness), but it cannot correct for astigmatism or presbyopia. It has a single point of focus, so most patients ask for the best distance vision when electing a monofocal lens. However, these patients often still need glasses for distance if they have significant astigmatism. In addition, nearly all patients will need at least reading glasses if they elect to see best at distance without glasses after their cataract surgery. Bifocals can help correct for both astigmatism and presbyopia, and patients can achieve good vision with them if they achieved good vision with bifocals prior to the development of cataracts.
Advanced Technology & Premium IOLs
Monofocal lenses are the default lenses covered by health insurance companies as part of the cataract surgery procedure. The lenses discussed below all come at an additional charge.
Multifocal IOLs (ReSTOR, Tecnis Multifocal)
Multifocal IOLs allow for full vision correction at near, intermediate and far distances, often completely eliminating the need for eyeglasses or contact lenses for many patients. Some multifocal IOLs can now also correct astigmatism.
All multifocal IOL’s can have a risk of causing glare with bright lights, loss of sharpness of vision in low light or at specific distances, and the possible need for glasses for certain visual tasks.
Extended Depth of Focus IOLs (Symfony, Symfony Toric)
Similar to Multifocal IOL’s, these lenses allow for an extended range of vision. Some of the additional benefits include a more continuous range of vision, and the lenses help correct for chromatic aberration. More critical near vision or lengthy reading often requires the use of low-power reading glasses. These lenses can also correct astigmatism.
All Symfony IOL’s can have a risk of causing glare with bright lights, starbursts, loss of sharpness of vision in low light or at specific distances, and the possible need for glasses for certain visual tasks. However, the risk is generally reduced compared to multifocal IOL’s.
Accommodative IOLs (Crystalens, Trulign)
Crystalens and Trulign are the only FDA-approved presbyopia correcting intraocular lenses (IOL) that correct vision through accommodation. The Crystalens IOL is made with flexible silicone that has hinges on each side allowing it to move with the eye muscle, flexing and accommodating so you can focus on the objects around you at any distance. In other words, it dynamically adjusts to your visual needs.
Accommodation is the ability to shift focus between nearby and distant objects, providing sharper vision at multiple distances in order to minimize the use of glasses. These lenses may still require low power reading glasses for near vision tasks if the lens is unable to accommodate the full range between distance and reading. However, they are less likely to cause glare or compromise sharpness of vision, and they can be used in patients with mild diseases of the retina.
Up until the availability of toric IOL’s, patients with astigmatism did not have the same opportunities that other cataract patients have had in correcting their condition with the types of IOL lenses that were available. Typically, the astigmatic patient would need an additional surgical procedure, such as refractive surgery or LASIK, to correct their vision after the procedure. If the patient did not want to undergo another surgical procedure, the only option for correction would be the use of either contact lenses or glasses to address their astigmatism.
Toric IOLs are able to correct for the condition of astigmatism, and are specially designed to correct astigmatism along with overall vision during cataract surgery. In most cases, a patient can achieve better than legal driving vision after surgery, but they will still need glasses for reading.