21st Sep, 2018

What is the difference between a multifocal and an accommodating IOL?

cataract surgery San Diego

What is the difference between a multifocal and an accommodating IOL?

During cataract surgery, the eye’s natural lens is removed and replaced with an artificial lens. This is known as an intraocular lens, or IOL. This procedure is necessary to restore vision when the natural lens has become cloudy. Many of our patients are focused simply on ridding themselves of the cataracts that have reduced their visual acuity. However, the choice of IOL that you make will have an impact on your vision for years to come.

While traditional monofocal IOLs are still an option and are chosen by many patients, there are also more advanced options. Both multifocal and accommodating IOLs will give you a better range of clear vision after placement. They do this in different ways, and there are pros and cons to each type of lens.

What is accommodation?

Accommodation is the process by which the eye’s natural lens changes shape, in order to change its focal distance. The ciliary muscle, which is located around the lens, pulls on the lens and causes the shape change. Changing the shape of the lens changes the focal point. (As people age, the lens becomes stiffer, which makes it harder for the lens to change shape enough to focus on objects up close.)

Monofocal IOLs

A traditional monofocal IOL is held securely within the ciliary muscle. It’s immovable, and it cannot change shape. It therefore has a single discrete focal point that doesn’t change. This is set for clear distance vision, so the patient will be free of glasses for distance activities, but will need reading glasses for near vision.

Many people who choose monofocal IOLs do so for budgetary reasons. These IOLs are the least expensive type available, and they are covered by insurance, including Medicare. Some patient’s don’t mind using reading glasses, and are satisfied with a monofocal IOL. For those who don’t mind paying a little more, there are two other options that can reduce or even eliminate the need for glasses after surgery.

Accommodating IOLs

With an accommodating IOL, the process of lens accommodation is simulated. The lens itself actually doesn’t change shape, but it is situated within the ciliary muscle in such a way that it moves forward or backward when the ciliary muscle contracts. Moving the lens forward or backward changes the focal point, allowing the eye to focus at different distances. The effect is that patients wearing accommodating IOLs are able to use a range of vision without glasses.

Some patients with accommodating IOLs are able to go without glasses completely, although this doesn’t happen for all patients; some still need glasses, especially for sustained near vision (such as reading). Accommodating IOLs do cost more than monofocal IOLs, and the excess cost is rarely covered by insurance, so they aren’t an option for all patients. However, for some patients, the ability to have clear vision across a range of distances is worth the extra cost.

Multifocal IOLs

A multifocal IOL also allows for vision at multiple different distances. However, instead of having a smooth range like an accommodating IOL, a multifocal IOL has multiple discrete focal points. The lens itself doesn’t move, but the brain can switch between the different focal points to see at different distances.

For most people, the brain quickly adapts to a multifocal IOL, and the patient is able to seamlessly transition between these different focal points. However, there are a few people who have trouble getting used to multifocal IOLs, and continue to find the experience a bit disorienting. An advantage of a multifocal IOL is that it’s generally better for near vision than an accommodating IOL, and is thus more likely to leave the patient completely free of reading glasses. Again, there will be an extra cost to choosing a multifocal IOL.

Which type is right for you? Cataract surgery San Diego

Each patient has to decide for themselves which type of IOL is right for them. There’s no one best option that’s right for everyone. For our patients having cataract surgery in the San Diego area, our surgeons are happy to talk through your options with you and help you make your decision.

Posted on September 21, 2018 By , in

Related Articles

Dr. P.