What is presbyopia?
the normal worsening of vision with age, especially near vision. As you
approach middle age, the
lenses in your eyes begin to thicken and lose their flexibility. The ability of
the lens to bend allows our eyes to focus on objects at varying distances
(accommodation). The loss of this ability means that
vision gets worse and objects cannot be brought into focus. This typically
becomes noticeable some time around age 40 when you
realize that you have to hold a book or newspaper farther from your face to
focus on it.
Normally, a muscle surrounding
the lens in your eye expands or contracts, depending on the distance to the
object you're focusing on. With presbyopia, the muscle still works, but it may
not work as well. Also, the lens loses much of its flexibility and won't bend
enough to bring close objects into focus. Images are then
focused behind the
retina instead of directly on it, leaving close vision
blurred. Putting greater distance between the object and your eye brings the
object into focus. For example, holding a newspaper farther from your face helps you see the words. For
this reason, presbyopia is sometimes called "long-arm syndrome."
What causes presbyopia?
Presbyopia is a natural
part of aging. As you grow older, the lenses in your eyes thicken. They lose
their elasticity, and the muscles surrounding the lenses weaken. Both these
changes decrease your ability to focus, especially on near objects. The changes
take place gradually, though it may seem that this loss of accommodation occurs
What are the symptoms?
The main symptom of
presbyopia is blurred vision, especially when you do close work or try to focus
on near objects. This is worse in dim light or when you are fatigued.
Presbyopia can also cause headaches or eyestrain.
How is presbyopia diagnosed?
usually be diagnosed with a general eye exam. Your doctor will
probably test your
visual acuity (sharpness of vision), your refractive
power (the ability of your eyes to change focus from near to far), the
condition of the muscles in your eye, and the condition of your
retina. He or she will probably also take measurements
for glasses or contact lenses at the time of the exam.
How is it treated?
Presbyopia can usually be
corrected with glasses or contact lenses. If you didn't need glasses or
contacts before presbyopia appeared, you can probably correct your eyesight by
using reading glasses for close work. Glasses you buy without a prescription
may be sufficient. But check with your eye doctor to find out the right
glasses for you. If you do buy glasses without a prescription, try out a few
different pairs of varying strength (magnification) to make sure you get
glasses that will help you read without straining.
already use glasses or contacts to correct
astigmatism, you'll need a new prescription that will
also correct presbyopia. You may wish to use bifocals, in which distant vision
is corrected at eye level and close vision is corrected at the bottom. Other
options include trifocal glasses, which can correct for distant, near, and
middle vision; progressive lenses, which give a smooth transition between
distant, middle, and near vision; bifocal contact lenses; or monovision contact
lenses, which correct distant vision in your dominant eye and close vision in
your weaker eye. Your prescription may have to be changed over time as
presbyopia gets worse.
If you don't want to wear glasses or
contacts, surgery may be an option to correct presbyopia. Procedures being used
to treat presbyopia include laser-assisted in situ keratomileusis (LASIK) and
photorefractive keratectomy (PRK). Both of these surgeries use lasers to
cornea of your eye. Laser surgery cannot give you both
distance and near vision in the same eye. But your doctor can correct one eye
for distance vision and the other eye for near vision.
option is clear lens extraction with an intraocular lens implant, in which the
natural lens is removed and an artificial one is implanted to replace it.
Some lens implants correct either
distance or near vision. Others (called multifocal implants) correct
both near and distance vision.
None of these surgeries will restore
perfect vision—you will have to compromise. For example, you may have surgery
to correct distance vision and then use reading glasses for near vision. Or you
may have one eye adjusted for near vision and one for distance vision, which
would reduce your depth perception. New procedures that reverse presbyopia are
being developed and tested.
Will your vision continue to get worse?
vision begins to decline due to presbyopia at around age
40. Your eyes continue to lose the ability to
accommodate—requiring changes to prescriptions for glasses or contacts—until
you reach your early 60s. Then accommodation stabilizes and your
vision should stop getting worse.