IOLs (Intraocular Lenses)

IOLs (intraocular lenses) are clear, artificial lenses that replace your eye’s natural ones. You receive IOLs during cataract surgery and refractive lens exchange. IOL implants correct a range of vision issues, including nearsightedness and age-related farsightedness. They may also help reduce your reliance on glasses for certain types of tasks.

What are IOLs?

IOLs (intraocular lenses) are clear artificial lenses that a healthcare provider will implant in your eye to replace your natural lens. Like glasses or contacts, IOL implants can correct vision issues such as:

IOL implants are permanent, meaning they stay in your eyes for the rest of your life. IOLs help improve your vision and may reduce your reliance on glasses in your daily routine. You receive IOLs during eye lens replacement surgery, most commonly during cataract surgery.

Who needs intraocular lens implants?

You may benefit from IOL implants if you:

  • Have cataracts that prevent you from seeing clearly. Virtually everyone undergoing cataract surgery will need to have an IOL implant in order to restore vision.
  • Have refractive errors that affect your vision, but you’re not a candidate for LASIK or other vision correction surgeries.

What are the different types of intraocular lenses?

There are many types of IOLs, each with its own pros and cons. The main drawback with some types of IOLs is you’ll still need to wear glasses for some tasks (like reading). Some IOLs can reduce your reliance on glasses, but you may notice side effects like glare around lights at night.

The list below covers some general categories of IOLs. Ask your ophthalmologist about which type of IOL is best for you. They’ll help you customize your IOL selection to suit your vision needs, lifestyle and personal preferences.

Monofocal lenses

This is the type of IOL that most people select. Monofocal lenses have one focusing power. This means they sharpen either your distance, mid-range or close-up vision. Most people set their monofocal lenses for distance vision, which can help with tasks like driving. You’ll probably still need glasses for close-up vision.

Monofocal lenses with monovision

Monofocal IOLs set to monovision are a good option for some people who want to rely less on glasses. Normally, the monofocal IOLs for both of your eyes are set to the same range (like distance). But with monovision, the lens for each eye has a different focusing power. For example, the lens for your right eye might correct for distance, with the lens for your left eye correcting for close-up vision.

With monovision, your eyes work together to help you see both distant and close-up objects. One drawback is that it takes some time to adapt to monovision. Some people can’t adapt to monovision at all. So, before choosing monovision IOLs, your provider may suggest you try monovision contact lenses for a couple of weeks. This allows you to see if this method of correction feels comfortable to you.

Multifocal lenses

Multifocal lenses improve your close-up and distance vision and may reduce your need for glasses. Unlike monofocal lenses, multifocal lenses contain several focal zones. Your brain adjusts to these zones and chooses the focusing power you need for any given task (like driving or reading). You may need some time to adapt to these lenses. But over time, you should be able to rely less on your reading glasses. Some people don’t need glasses at all.

One drawback of multifocal lenses is that you may notice rings or halos around lights, like when driving at night.

Extended depth-of-focus (EDOF) lenses

Unlike multifocal lenses, EDOF lenses contain one long focal point that expands your corrected range of vision and depth of focus. These lenses give you excellent distance vision along with improvements in your mid-range vision (for tasks such as computer use). You may still need to use glasses for close-up tasks like reading.

Accommodative lenses

These lenses are similar to your eyes’ natural lenses in that they adjust their shape to help you see close-up or distant objects. Accommodative lenses are another option to help reduce dependency on glasses. But you may prefer to use glasses if you’re reading or focusing on close-up objects for longer periods of time.

Toric lenses

Toric lenses help people who have astigmatism. These lenses improve how light hits your retina, allowing you to have a sharper, clearer vision. Toric lenses are available in monofocal, multifocal, extended depth of focus (EDOF) or accommodative models. They serve to improve the quality of the vision delivered. Toric lenses will help reduce the amount of glare and halos artifacts commonly experienced by people with astigmatism.

Light-adjustable lenses (LALs)

Light-adjustable lenses are different from other IOL options in that your ophthalmologist fine-tunes their corrective power after your lens replacement surgery. They do this through a series of UV light treatment procedures, spaced several days apart. These procedures customize your lens prescription to bring you as close to your desired visual outcome as possible. This is still a type of monofocal lens, so glasses will be necessary for reading or driving.

Phakic lenses

Phakic lenses are typically implanted in younger individuals while trying to preserve the natural human lens, to correct for near-sightedness in people who don’t qualify for laser refractive surgery. This helps preserve your natural ability to focus and accommodate. These lenses will eventually have to be removed during cataract surgery but can offer younger people clear vision for a long time.


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Which intraocular lens is best for me?

Your ophthalmologist will determine if you would benefit from cataract surgery, or if you would qualify for a refractive lens exchange surgery. They’ll discuss your options and help you decide which IOLs are best for you. They’ll also conduct a thorough eye exam to check your vision and the health of your eyes. They’ll perform some simple, painless tests to measure your eye size and shape, too.

To prepare for a conversation with your ophthalmologist, you should think about your priorities for your IOLs, as well as aspects that aren’t as important to you. It may help to ask yourself the following questions:

  • Am I OK wearing glasses sometimes? If so, how often and for what types of tasks?
  • What kind of vision is required in my work/profession? Am I OK wearing glasses for these tasks?
  • Do I drive often at night? If so, can I adapt to seeing glare and halos around lights when I drive?
  • What kind of hobbies and activities do I enjoy the most and how much dependency on glasses am I OK with for these activities?
  • What is my budget for surgery?

Most insurance plans cover monofocal lenses, but you may have to pay for other types out of pocket. Be sure to find out the cost of various IOL options before making your final decision.

What are possible issues and complications related to IOL implantation?

Most IOL complications are rare and include:

  • Posterior capsular opacification:This is commonly known as a secondary cataract. This happens after many months or years when a film-like material grows behind the implanted lens. This is a normal process that happens after surgery and can be expected to occur over time for almost everyone. The treatment for this is very quick and straightforward and is usually performed using a laser in the office.
  • IOL dislocation: This means your IOL shifts from its normal position. You face a higher risk if you have certain eye conditions, like pseudoexfoliation syndrome, or have had trauma or prior eye surgeries. Certain genetic disorders, such as Ehlers-Danlos syndrome and Marfan syndrome, may also raise your risk. In some cases, you may need surgery to reposition or replace the IOL.
  • Uveitis-glaucoma-hyphema (UGH) syndrome: UGH syndrome occurs when an IOL irritates your iris and other parts of your eye. This leads to inflammation, raised intraocular pressure and other symptoms. As with IOL dislocation, you may need surgery to reposition or replace the IOL. This is an extremely rare complication that most people don’t experience with routine surgery.
  • IOL opacification: This is a clouding of your IOL. Your vision may become less sharp, and you may notice glare around lights. Treatment involves surgery to give you a new IOL. This is extremely uncommon with modern-day IOLs.
  • Refractive surprise: A refractive surprise is when your vision after IOL implantation isn’t as sharp as you and your ophthalmologist expected. Your ophthalmologist will suggest a range of solutions. You may decide to accept the vision correction as is and do nothing further. Or you can choose to wear glasses, have laser vision correction (such as LASIK or PRK) or have an IOL replacement surgery.

Talk with your ophthalmologist about possible complications and your level of risk before choosing to have IOLs implanted in your eyes. They’ll tell you what to expect based on your medical history, eye health and other factors. Also, ask them about common side effects associated with cataract surgery or refractive lens exchange. Be sure to get all the information you need to make the decision that’s right for you.

A note from Cleveland Clinic

IOLs (intraocular lenses) help many people see the world more clearly than ever before. As technology continues to evolve, IOLs will offer more features with fewer drawbacks. As you choose your IOLs, it may help to make a list of your priorities (the features that are most important to you). Also, write down the aspects that are nice but not necessary. Share this information with your ophthalmologist to help guide your shared decision-making process.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/18/2023.

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