Issue 50.13
Before intraocular lenses (IOLs) were developed, people had to wear very thick eyeglasses or special contact lenses to be able to see after cataract surgery. Now, with cataract lens replacement, several types of IOL implants are available to help people enjoy improved vision. Discuss these options with your eye doctor to determine the IOL that best suits your vision needs and lifestyle.
Like your eye’s natural lens, an IOL focuses light that comes into your eye through the cornea and pupil onto the retina, the sensitive tissue at the back of the eye that relays images through the optic nerve to the brain. Most IOLs are made of a flexible, foldable material and are about one-third of the size of a dime. Like the lenses of prescription eyeglasses, your IOL will contain the appropriate prescription to give you the best vision possible.
Which lens option is right for you?
Before surgery your eyes are measured to determine your IOL prescription, and you and your eye doctor will compare options to decide which IOL type is best for you, depending in part on how you feel about wearing glasses for reading and near vision. The type of IOL implanted will affect how you see when not wearing eyeglasses. Glasses may still be needed by some people for some activities.
Intraocular lens (IOL) types:
Monofocal lens
This common IOL type has been used for several decades. Monofocals are set to provide best corrected vision at near, intermediate or far distances. Most people who choose monofocals have their IOLs set for distance vision and use reading glasses for near activities. On the other hand, a person whose IOLs were set to correct near vision would need glasses to see distant objects clearly.
Presbyopia is a condition that affects everyone at some point after age 40, when the eye’s lens becomes less flexible and makes near vision more difficult, especially in low light. Since presbyopia makes it difficult to see near objects clearly, even people without cataracts need reading glasses or an equivalent form of vision correction.
Multifocal or accommodative lenses
These newer IOL types reduce or eliminate the need for glasses or contact lenses. In the multifocal type, a series of focal zones or rings is designed into the IOL. Depending on where incoming light focuses through the zones, the person may be able to see both near and distant objects clearly.
The design of the accommodative lens allows certain eye muscles to move the IOL forward and backward, changing the focus much as it would with a natural lens, allowing near and distance vision. The ability to read and perform other tasks without glasses varies from person to person but is generally best when multifocal or accommodative IOLs are placed in both eyes.
Toric IOL for astigmatism
This is a monofocal IOL with astigmatism correction built into the lens. Astigmatism: This eye condition distorts or blurs the ability to see both near and distant objects. With astigmatism the cornea (the clear front window of the eye) is not round and smooth (like a basketball), but instead is curved like a football. People with significant degrees of astigmatism are usually most satisfied with toric IOLs.
If you’re interested in learning more about cataracts and intraocular lenses from the ophthalmologist’s perspective, call Richens Eye Center to schedule your next comprehensive eye exam at (435) 216-1226.