Eye Care - Presbyopia
Hold the book up close and the words appear blurred. Push the book farther away, and the words snap back into sharp focus.
That’s how most of us first recognize a condition that eye care professionals call presbyopia, a name derived from Greek words meaning "old eye." Eye fatigue or headaches when doing close work, such as sewing, knitting or painting, are also common symptoms.
Because it is associated with aging, presbyopia is often met with a groan -- and the realization that reading glasses or bifocals are inevitable.
What causes presbyopia?
Recent research shows that the lens in the eye continues to grow as we age.
Eventually it reaches a point, around the age of 45 that it is too big for the
muscles that normally change it's shape to work effectively. The loss is
gradual - but inevitable.
Our ability to "see" starts when light enters the eye through the cornea. The shape of the cornea, lens, and eyeball help bend (refract) light rays in such a manner that light is focused into a point precisely on the retina.
The crystalline lens plays a key role in focusing light on the retina. With the help of tiny ciliary muscles, it changes shape, or accommodates, for both near and distant objects by bending or flattening out to help focus light rays. However, as one ages, not only does focusing on near objects become more difficult, the eye also is unable to adjust as quickly to rapid changes in focus on near and distant objects.
When does it occur?
The age at which presbyopia is first noticed varies, but it usually begins to interfere with near vision in the early 40’s.
How is the problem
diagnosed?
An accurate, thorough description of symptoms and a comprehensive eye health
examination, including a testing of the quality of your near vision, are
necessary to diagnose presbyopia.
How is presbyopia
treated?
Usually, the treatment for presbyopia is prescription eyeglasses to help the
eye accommodate for close-up work. Prescription lenses (reading glasses) help
refract light rays more effectively to compensate for the loss of near vision.
If you do not have other vision problems, such as nearsightedness or astigmatism, you may only need glasses for reading or other tasks done at a close range. If you have other refractive errors, such as nearsightedness, bifocal or progressive addition lenses (in which the power of the lens changes gradually towards the bottom to allow reading, without the reading portion of the bifocal lens obviously visible) are often prescribed.
Can I still wear contact
lenses?
Yes, you have several options with contact lenses: Bifocal contact lenses,
monovision, varifocal and normal distance contact lenses with reading spectacles.
Generally, bifocal contact lenses are not yet as successful as the normal
"single vision" ones.
What lens option will
work best for me?
Your eye care professional may ask a number of questions to help determine the
best avenue of treatment. You may be asked to describe your usual lifestyle or
daily activities and from this your practitioner will be able to recommend a
solution most suited to your needs. For instance, if you are a librarian, your
needs will be significantly different from those of a truck driver.
Once my vision is
corrected for presbyopia, will I require frequent lens changes?
Presbyopia is a gradual change, happening over a number of years so your
prescription will need to be updated periodically. Changes are best made at
your regular eye examination rather than after the need for change starts to
cause you difficulties.