Understanding Intraocular Lenses (IOLs): A Patient’s Guide

The world of IOLs has changed beyond imagination over the last decade. If you’d looked at the different types of IOLs back then, you’d have had a very short list to scroll through. Today, choosing an intraocular lens is something that should be done in conjunction with your surgeon, taking into account things like your lifestyle, eye anatomy, and your expectations.

A Simple Guide to IOLs 

The first thing to understand is what an IOL is. When a cataract forms, it blocks light flow through the natural lens in the eye. When you undergo cataract surgery, this lens is removed and replaced with an artificial one—an intraocular lens.

The natural lens is a magnificent piece of nature’s engineering. It focuses the light that enters the eye, shining it on a thin film of cells (the retina) at the back of the eye. These light signals then traverse the optic nerve to the brain, where they’re translated into what we see. The lens works with other parts of the eye, such as the cornea and eye muscles, to bend the passage of light, which also means it plays a role in focusing on different distances.

Today’s most advanced IOLs can mimic this natural function, potentially allowing for a life without any additional eyeglasses or contact lenses, or only needing them for close-up vision.

Different types of IOLs

IOLs range from the simple, monofocal lens to cutting-edge examples, such as the Clareon PanOptix Pro.

Without delving too much into the individual manufacturers, the following are the main types of IOLs to choose from:

• Monofocal: As the name suggests, a monofocal lens provides you with focused vision at a single distance. In most cases, this will be at distance (unless you have a particular need for it to be near distance), and you’ll wear eyeglasses for close-up work. For many years, this was the only option and is still the only type of IOL that is fully covered by Medicare (and many medical insurance policies). But, if you do want a more advanced lens, you will usually only pay the additional cost, rather than the full amount.
• Multi-focal: You can think of these as a little like bi- or tri-focal eyeglasses. The prescription is built into the lens—most usually for near and far vision—so when you shift your gaze, you can focus on different distances. However, there are some that can also correct intermediate vision as well. Multi-focal IOLs are not to be confused with the ones mentioned below, as these provide vision at different distances in alternative ways.
• EDOF: Standing for “extended depth of focus”, this is where technology starts to get really clever. These lenses bend the light that enters the eye, creating a long, single focal point, much as the natural eye lens does. While this might sound as clear as mud, what it means is that the eye can naturally shift focus to different distances, without specific areas of the lens having different prescriptions. In effect, it elongates the focal point, which results in the ability to smoothly and continuously shift focus from distance to intermediate vision. You will, however, probably need to wear glasses for close-up work, such as reading.
• Accommodative: These are the closest IOL on the market that mimic the abilities of a young, healthy, natural lens. If your aim is to wear glasses at all, then this is likely to be the gold standard. There are many different types of accommodative lenses, but each aims to provide you with focused vision at all distances and uses the muscles of the eye to deliver.
• Toric: These are specifically for correcting astigmatism, a common condition that, according to the American Academy of Ophthalmology, affects around one-third of Americans.
• LAL: Another very new type of IOL, this stands for “light-adjustable lens” and is the only type that can have a prescription tweaked while still in the eye. They can correct astigmatism and provide both near and far focus. Once the prescription is adapted for your needs, it’s locked-in and can no longer be altered.

Not all lenses are suitable for everyone, which is why an in-depth pre-op discussion with your surgeon is needed. All lenses, apart from monofocal, are referred to as “premium” and require laser-assisted, rather than traditional cataract surgery. Many things will determine which type/s might be suitable for you, including your prescription, eye anatomy, co-existing eye and medical conditions, etc.

You will also find that not every surgeon offers all types of lenses. This is usually down to not having the training and equipment to perform laser-assisted surgery, as well as a lack of patient education.

However, premium IOLs can offer a significant uplift in quality of life for many, making a discussion about the art of the possible crucial before making a decision.

Want to find out more? Visit https://www.moderncataractsurgery.com/ and call today to book a consultation.