The most commonly used lens implant is called a monofocal lens, which is the lens that is covered by all insurance plans. This lens focuses light for one distance and one distance only. In the vast majority of patients, a lens power is chosen so that distant (far away) vision is as clear as possible with limited glasses, but vision at the intermediate (computer) and near (reading) areas is quite blurred without glasses. So, we typically say patients will be fully dependent on glasses for intermediate and near activity. Your distance vision and need for glasses will be dependent on the residual refractive error as we discussed above. The monofocal lens assumes the eye is a perfect sphere and provides the clearest outcomes when an eye has minimal or no astigmatism. Astigmatism, which is when your cornea is shaped more like a football than a basketball (or perfect sphere), does not allow for light to focus to a single point and glasses may sometimes be needed to correct this astigmatism, when a monofocal lens is used. The more astigmatism the eye has, the stronger the glasses will be needed to achieve the clearest vision for all activities (distance, intermediate and near) after surgery. In the event that you are an avid reader and most of your day is spent performing near activities, you may opt to remain near sighted so that you can read without glasses, but you will be dependent on glasses for computer work and far activities like driving or watching a television.

The toric monofocal lens is a specialized lens that corrects astigmatism and allows the eye to focus light closer to a single point on the retina reducing or eliminating the need for glasses for your desired location of clear vision (distance, intermediate, OR near). Toric lenses do not always correct all astigmatism because there are gaps in the available strengths of lenses and sometimes your astigmatism falls in-between these strengths. Think of it as a shoe size. Let’s say you wear a size 9 but a shoe is only made in size 8 and 10. You will have a shoe that covers your foot and allows you to walk on rough roads much better than bare feet but the shoe does not perfectly fit your foot. But a pair of thick or thin socks can help that shoe fit better. In patients with severe astigmatism, glasses will absolutely be required to see at distance, intermediate and near. When compared to a monofocal lens, a toric lens can drastically reduce the need for glasses at a distance and sometimes allow for a patient to function without glasses for distance activities, BUT a small pair of glasses may still be needed for best vision. This lens is a good option for someone with astigmatism that wishes to minimize their need for glasses for far away activities and understand that readers will be needed for intermediate and near activities if we elect to maximize the far away vision.

When patients desire an extended range of vision to include some intermediate and near vision, multifocal lens implants can be used. Multifocal lenses use a technology that splits or shares light as it enters the eye–one third of the light rays are used for distance vision (television/street signs), a third are used for intermediate (computer) and a third used for the near (phone,book, and/or iPad/tablet). There are several multifocal lenses on the market and the most commonly used multifocal lens is the Clareon PanOptix multifocal lens. Multifocal lenses provide the best outcome when implanted in both eyes, allowing for both eyes to see very similar images at all levels of vision. We have had very good outcomes with this type of lens and studies have shown that 94% of patients would still choose the PanOptix if they were able to go back in time and repeat the cataract surgery. As much as we wish this was a perfect technology, there are drawbacks that need to be discussed.

Because light is split and shared, there may be a slight reduction in contrast sensitivity (ability to distinguish two very similar shades of a color), so we do not recommend that patients with significant eye diseases like glaucoma or macular degeneration have these lenses implanted. Patients report having some glare and describe seeing halos around lights, especially at night. These lenses also have very definitive focal points, so the intermediate vision is an arms-length away from your eyes and the near vision focal point is about 18-inches away from your eyes. Objects in-between these focal points will be blurred. In addition, a small percentage of patients continue to require a small pair of reading glasses to see fine print or may need proper lighting to see objects clearly at near (reading fine print, reading a menu in a dark restaurant, threading a needle).

https://www.myalcon.com/ca/en/panoptix/ 

If the glare is too strong, the multifocal lens can be exchanged for a different lens technology within the first 4-6 months after the initial cataract surgery but this is very rare and patients report that the glare improve over time.

Another option that provides an extended depth of focus that improves the intermediate and near vision is the Aphthera presbyopia-correcting small aperture lens. It has a light filtering ring on the optic that filters out distorted low quality light and allows for high quality light rays to focus directly onto the retina. This provides a seamless range of vision from distance to near, which differs from the multifocal lenses that have very specific focal points. This means an object will be relatively clear regardless of the distance from the eye. The Aphthera lens is typically implanted in the non-dominant eye while a monofocal-type lens (monofocal, monofocal toric or the Light Adjustable Lens) is implanted for distance vision in the dominant eye. The non-dominant eye may be left a little near-sighted to provide the clearest reading vision leading to imperfect but relatively clear distance vision. Some patients report seeing a mild amount of halos at night while other report a slight reduction in their peripheral vision. Because light is not split, the contrast sensitivity is similar to the monofocal lens, however, some patients report that their vision is a little “darker” compared to a monofocal lens.

https://www.bauschsurgical.com/cataract/ic-8-apthera-iol/

The RxSight Light Adjustable Lens (LAL) is a unique lens in that the power of the lens can be modified after surgery to ensure the clearest vision. Despite being monofocal in nature, the lens does have an extended depth of focus providing some intermediate and near vision. When there is a desire to minimize reading glasses, the non-dominant eye can be adjusted and left a little near-sighted without removing much of the clarity for distance vision. The unique aspect of this lens is its ability to have its power modified after implantation. This is important because most patients have some level of refractive error after surgery which reduces the overall clarity of vision. The LAL offers LASIK-like accuracy to your cataract surgery. Also, by adjusting the lens power after surgery, we can customize your vision and tailor it to your specific needs. Because the lens polymers are locked in place by ultraviolet light, patients need to protect the lens with UV blocking glasses until the desired lens power is “locked-in”, which is performed in the office approximately six weeks after surgery. While most patients are able to read without glasses, there is still a small percent that may require a small pair of reading glasses to read fine print.

https://rxsight.com/patients/