Topic Overview
What is presbyopia?
Presbyopia is 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 generally becomes noticeable some time around age 45
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. 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 and 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 quickly.
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?
Presbyopia can usually be diagnosed with a general eye exam. Your
health professional 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 determine 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 allow you to read
without straining.
If you already use glasses or contacts to correct
nearsightedness,
farsightedness, or
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 adjusted 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 reshape the
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.
Another 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. You can choose either traditional lens implants, which
correct either distance or near vision, or bifocal lens implants.
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?
Near vision begins to decline due to presbyopia at around age 45.
Your eyes continue to lose the ability to accommodate—requiring changes to
prescriptions for glasses or contacts—until you reach your early 60s. At this
point, accommodation stabilizes and your vision should stop getting
worse.