LASIK - a Cure for Blurry Vision?
Presbyopia is an eye disorder that normally sets in between the
ages of 40-50. A lot many theories have been suggested to
delineate its proper cause. However, the most convincing theory
is that the eye lens loses its elasticity over time, and this in
turn results in the loss of accommodation power of the lens.
Consequently, the lens is unable to focus on nearby objects, and
hence the patient's near vision is rather blurry. Presbyopia
affects everyone at a certain age and it is not routinely
curable.
The loss of accommodation power can be compensated for through
LASIK surgery by producing what's called "monovision". Normally,
people possess binocular vision. That is, both eyes work
together equally while viewing an object. On the other hand, in
case of monovision, one eye is corrected for near vision and the
other is corrected for distant vision. LASIK surgeons make use
of this technique to counter presbyopia.
LASIK can be a viable option for producing monovision. However,
there is a caveat. Monovision is not appropriate for everyone.
Furthermore, monovision may also interfere with depth
perception. That is, the patient may not be able to perceive the
accurate distance of any object, since accurate 3D perception
requires input from both eyes. Therefore, it is recommended that
the patient first uses contact lenses to produce monovision, in
order to ensure that he or she can adapt to the change. Apart
from surgery, a patient may use prescription glasses (bifocal or
progressive) to compensate for the loss of power of
accommodation.
Intraocular lens implant is another viable alternative to
counter presbyopia. In essence, the natural lens is replaced
with a new lens to achieve accurate refraction. Another
interesting aspect is that presbyopia may not have a major
affect on people with myopia. In general, a myopic does not have
trouble reading without glasses. Thus a myopic often possesses
perfect reading vision, without any visual aid, even in the old
age and even after presbyopia sets in.