Surgery for cataracts involves removing the natural lens of the eye
that contains the
cataract and either replacing it with an artificial
lens called an intraocular lens implant (IOL) or compensating for its absence
with eyeglasses or contact lenses. See a picture of the
lens
.
The most common replacement is an IOL. Before having surgery, review
with your doctor the advantages and disadvantages of each type of replacement
lens. A variety of IOL types are available, and your doctor can help you choose
the type that may work best for you.
An IOL is placed inside the eye during surgery. Corrective glasses
may be needed after surgery for reading and close work, but they are not as
thick and heavy as traditional cataract glasses.
IOLs are commonly chosen to provide better distance vision than near
vision, and glasses are used for sharp near vision. However, some people choose
IOLs that provide better near vision for reading and use glasses for distance
vision.
If you are having the lenses in both eyes replaced, your doctor may
recommend monovision. With monovision, the IOL in one
eye provides for better near vision, and an IOL that gives better distance
vision is implanted in the other eye. Most people who try monovision can adjust
to it. Monovision has some drawbacks, however. Each eye must work more
independently, which can cause problems with depth perception. You may have to
adjust your gaze more often to allow one eye or the other to see
properly.
When thinking about how an IOL will affect your vision following
cataract surgery, the two main types of IOL to consider are:
- Monofocal IOLs. This type of intraocular lens is
shaped to provide good vision in just one particular range of distances, either
near or distance vision. If you have this type of IOL implanted in your eye(s),
you will probably need glasses to provide clear vision in the other range. For
example, it is common for the IOLs to be chosen to provide better distance
vision than near vision, and glasses are used for sharp near vision. This is
the most common choice.
- Multifocal IOLs. This type of intraocular lens
design provides correction for both near and distance vision, and both near and
far objects can be in focus at the same time. Your brain must learn to select
the visual information it needs to form an image of either near or distant
objects, so multifocal IOLs may require some adjustment. A person may adjust
better to multifocal IOLs if they are placed in both eyes. Not everyone is a
candidate for this type of lens.
If you are considering cataract surgery to replace the lens in your
eye(s), you should discuss with your doctor which of the different types of IOL
is most likely to work best for you.
IOLs may not be used in infants younger than age 2.
IOLs are now being used more commonly in children. However, some
controversy still exists over their suitability for very young children, since
it is not clear how well the material IOLs are made of will last over a
lifetime.1
Studies are being done to determine the age at which children can
begin to benefit from an IOL. If your child needs cataract surgery, talk with
your eye specialist (preferably a pediatric ophthalmologist) about what current
studies are showing about the use of IOLs in children.