Reading your eyeglass or contact lens prescription is often the
first step to understanding if conventional or custom
wavefront
Lasik,
All-Laser Lasik,
PRK,
LASEK,
Epi-Lasik,
NearVision CK,
RLE, or any
refractive surgery procedure is appropriate for you. You should
understand your glasses and contact lens prescription even before
you select a
Lasik Laser Eye Surgery Doctor.
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Refractive error, or the degree from which you do not have normal
vision, is commonly measured in
diopters. A diopter is often represented by a capital "D" in
a prescription. No refractive error is referred to as "plano", often
represented as "pl". The greater the refractive error, the larger
the number for both
sphere,
representing the amount of
myopia or
hyperopia, and and cylinder, representing
astigmatism. This known as a spherocylinder or spherocylindrical
prescription.
A typical spherocylindrical prescription would look like:
| |
sphere |
cylinder |
axis |
|
OD: |
-2.75 |
-1.25 |
x15 |
|
OS: |
pl
|
-0.75 |
x85 |
OD is an abbreviation for the Latin oculus dexter, meaning
right eye. OS is an abbreviation for the Latin oculus sinister,
meaning left eye. The first number after the determination of which
eye is the sphere. A negative number indicates myopia. A positive
number indicates hyperopia. The second number in this prescription
is the cylinder (astigmatism), and the third number is the axis
of the cylinder component. The axis of the astigmatism does not
relate to the amount of cylinder, just the location of the irregularity.
If the patient has no cylinder, then the last two columns may remain
blank, or "DS" for "diopter sphere” may be used.
This prescription shows that the patient has 2.75 diopters of
myopia with 1.25 diopters of astigmatism at an angle of 15 degrees
in the right eye, and the left eye is plano with 0.75 diopters of
astigmatism at an angle of 85 degrees.
