Intraocular Lenses — Types, Costs, and How They Work

A cataract is a clouding of the eye’s lens. There are many potential causes for cataracts, including diabetes, but the most common cause is age. In fact, more than half of all people either will have a cataract or will have had cataract eye surgery by the time they reach the age of 80.

Cataracts are often accompanied by a refractive error such as nearsightedness, farsightedness, or astigmatism. Intraocular lenses are the solution to these problems. An intraocular lens (IOL) is a lens that is implanted in the eye, usually replacing the existing crystalline lens because it has been clouded over by a cataract. Your lens implant will determine whether you will need glasses or contact lenses after cataract surgery, and what your prescription will be if you do.

Intraocular lenses have been around since the mid-1960s, but it wasn’t until 1981 that the FDA approved them for use. Before 1981, if you underwent surgery to remove your cataracts, you had to wear extremely thick eyeglasses or special contact lenses to see. IOLs are designed to address the loss of vision that is associated with cataract surgery. IOLs fall into different categories, including monofocal, multifocal, monovision, toric, silicone, blue-light, piggyback, and aspheric.

Types of Monofocal and Multifocal IOLs

Monofocal lenses are the traditional IOLs that offer vision from only one distance, whether it’s far, intermediate or near. Unfortunately you must wear eyeglasses or contact lenses in order to be able to read, use a computer, or view objects in the middle distance, especially if you had been experiencing presbyopia (loss of clear close-up vision) before the cataract surgery.

Multifocal lenses, also known as accommodating lenses, are the newest type of IOL. They allow you to see at more than one distance without the need of eyeglasses or contact lenses. There are different multifocal lenses available on the market:

AcrySof ReStor uses a diffractive technology and a design that responds to the width of the eye’s pupil in order to provide near, intermediate, and distance vision. This lens is said to improve contrast sensitivity and provide better nighttime vision than other types of multifocal IOLs. Studies show that 80 percent of people who have this type of lens implanted have had no need for eyeglasses or contact lenses.

ReZoom is a multifocal refractive IOL that distributes light over five optical zones to provide near, intermediate, and distance vision. Studies show that 93 percent of people reported never or only occasionally needing glasses.

Crystalens HD was designed to restore the eye’s accommodation ability, which is reduced as presbyopia progresses. In FDA studies, about 80 percent of people who received the Crystalens HD could see at the near vision equivalent of 20/20 after four months. It also hinges on both sides of the IOL, and it can be moved more easily by the ciliary muscle. This allows the eye to focus more naturally at a greater range of distances. So far, Crystalens HD is the only accommodating IOL that has been approved by the FDA.

Synchrony is a dual-optic IOL that is showing promise, but hasn’t been approved yet by the FDA. In small case studies this IOL has demonstrated the ability to restore focus at a range of 1.00 to 5.00 diopters, which is about twice that of a control group.

What Are Toric IOLs?

Just like regular contact lenses, toric IOLs are meant to correct astigmatism. Staar Surgical IOL was the first toric IOL available in the United States. The Staar toric IOL comes in a full range of distance vision powers, and in two versions: one that corrects up to 2.00 diopters, and another that corrects up to 3.50 diopters of astigmatism. Talk with your eye doctor about other types of toric IOLs.

What Are Silicone IOLs?

The FDA has approved intraocular lenses made of silicone, which includes the STAAR Elastimide Lens (3-piece silicone IOL) and the STAAR Elastic Lens (1-piece silicone IOL). Both are available in various diopter powers. STAAR Surgical Company was the first company to receive pre-market approval for a foldable single-piece silicone IOL. The lens’s ability to be folded enables surgeons to make a small “no stitch” incision during cataract eye surgery, and results in a quicker recovery time.

What Are Aspheric IOLs?

Aspheric IOLs, which were first launched by Bausch & Lomb in 2004, are slightly flatter than spherical lenses in the periphery, and are designed to provide better contrast sensitivity. There is a debate, however, about how long this contrast sensitivity can last in older patients, since the ganglion cells of the retina play a major role in determining contrast sensitivity, and we gradually lose those cells as we age. There are different options available if you and your doctor choose to use aspheric IOLs. These options include:

SofPort Advanced Optics IOLs are designed to be aberration-free, and SofPort is the first and only IOL with two aspheric surfaces for optimal visual outcomes.

AcrySof SN60WF is designed to compensate for spherical aberrations by addressing the effects of over-refraction at the periphery. This is accomplished without increasing edge thickness. It also includes the blue light-blocking feature, which ranges from 400 nm to 500 nm in the visible light spectrum, and filters UV light and high-energy blue light.

What Are Blue-Light Filtering IOLs?

These filter both ultraviolet and high-energy blue light, which are present in natural and artificially produced light. For a long time now, UV rays have been suspected to cause cataracts and other vision problems, and many IOLs filter them out just as your natural crystalline lens does.

What Are Piggyback IOLs?

Piggyback IOLs are an option only if you have a less than satisfactory result from your original cataract surgery. To put it simply, an additional lens is inserted on top of the one you currently have. Your doctor may suggest this option if you require an extremely high degree of vision correction. The combination of two strengths could help your vision dramatically.

What Is Monovision?

If you need cataract surgery in both eyes, your doctor might have you consider monovision. Monovision involves implanting one type of IOL in one eye to provide near vision and a different IOL in the other eye to provide distance vision. People who have previously used monovision with contact lenses tend to adjust more easily to this method. This method is mainly considered for people suffering from presbyopia.

Problems with monovision include loss of depth perception due to reduced binocular vision, difficulty adjusting, and blurred vision at both near and far distances because your eyes are not working together as they did before. If you can’t adjust to monovision after your cataract surgery, you might regret not choosing a multifocal or accommodating IOL instead. Some surgeons, at your request, will trial-fit a cataract patient in monovision contact lenses prior to inserting monovision IOLs, since once the surgery is complete you can’t go back.

IOL Surgery — Before, During, and After

This procedure can be done under local anesthesia. The doctor will utilize a flexible IOL that enables the lens to be rolled for insertion and into the capsule through a very small incision. This eliminates the need for stitches. The whole procedure usually takes less than thirty minutes, and the recovery period is about two to three weeks.

After surgery, patients are told to avoid any strenuous exercise or anything else that significantly increases blood pressure. They should also visit the ophthalmologist regularly for several months to monitor the implants.

Why Use Phakic Intraocular Lenses?

Phakic intraocular lenses (PIOLs) are used to treat myopia and hyperopia, and they differ from other types of IOLs in that they do not require they eye’s natural lens to be removed. Read more about PIOLs here.

What Are the Complications of Traditional IOLs?

The IOL implantation of monofocal lenses carries several risks, such as:

  • infection
  • loosening of the lens
  • lens rotation
  • inflammation
  • nighttime halos

Though IOLs enable many people to reduce their reliance on glasses, most patients still need glasses for activities like reading.

What Is the Cost of Intraocular Lenses?

Costs will need to be discussed with your cataract surgeon. Cataract surgery and traditional IOLs are covered by Medicaid and Medicare. The newer products are not, so you might be footing a good part of the bill if you elect one of them. Depending on the surgeon and the IOL used, it could cost you up to $2,500 or more per eye, even with insurance.

Talking to Your Eye Doctor

Questions to ask your eye doctor about IOLs:

  • Which type of IOL would work best for me?
  • Am I a candidate for monovision?
  • How much will my IOLs cost per eye?
  • Do you have written instructions for preparing for cataract surgery?
  • If complications arise, how long should I wait to contact you?
  • Will I need to wear eyeglasses or contact lenses with my IOLs?