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Presbyopia & Monovision
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What is presbyopia?
Presbyopia is the loss of our accommodative or focusing ability for
reading and near work. Everyone becomes presbyopic with age.
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Typically, by the time we reach our forties, we require a vision
aid such as reading glasses or bifocals to help us focus on objects
located near us. However, not every presbyope will need near correction.
Nearsighted myopic people may simply take their glasses off to read.
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What is Monovision?
There is a Lasik treatment option available to minimize the impact of presbyopia.
It is possible to surgically correct one eye for distance vision and leave
the other slightly nearsighted for reading vision. This technique, called
monovision, may give presbyopes the best chance of eliminating corrective
eyewear (for a period of time).
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Usually, the dominant eye is corrected for distance vision and the
non-dominant eye for near vision. Normally, this slight difference
between the eyes is quite easily managed. |
The brain makes these changes automatically with time, without any conscious
effort or awareness. Many of our presbyopic patients have chosen this type
of surgical correction and have eliminated or at least minimized the need
for glasses for a period of time.
As with many good things in life, monovision
comes with some slight disadvantages.
First, it takes time to develop a tolerance
to monovision. This adjustment period
may take several days to several months.
During this adjustment period, your
vision may appear to be slightly blurred.
Although it may feel somewhat awkward,
patients do not generally complain of
headaches or dizziness. When given sufficient
time, the vast majority of patients
eventually adapt well to monovision.
Second, it is important for patients
to understand that monovision is set
for a specific reading distance. Monovision
does not give you unlimited
range to your near vision. If near vision
is perceived as too close or too far
away, it may easily be adjusted with
a subsequent laser procedure. In rare
cases, if a patient finds it intolerable,
monovision may be completely reversed.
Finally, glare and halos may be present at night time. Seventy percent of
patients experience no long term effects. Thirty percent of monovision patients
must rely on driving glasses to minimize the glare and halo to an acceptable
level. Most patients find this to be acceptable because they use their reading
vision much more frequently than their night driving vision.
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