Reading Your Prescription
Your eyeglass prescription was written by an optometrist, ophthalmologist, or orthoptist for eyeglasses. It specifies the refractive power to which the eyeglasses are to be made in order to correct blurred vision due to refractive errors, including myopia, hyperopia, astigmatism, and presbyopia. Eyeglass prescription issued by different doctors may differ in format, but they somewhat look like the one below
When ordering prescription eyeglasses online, be sure your eye doctor writes your Pupil Distance (PD) measurement on your prescription. This ensures the optical center of your lenses will be exactly in front of your pupils
- Look at the prescription. The OS means your left eye and the OD means your right eye. There will be a plus or minus sign in front of the numbers. A plus sign means you are farsighted and a minus sign means you are nearsighted. The higher the numbers, the more your vision needs correction
Check to see if you have astigmatism. If you do, your prescription will look like this:
SPH x CYL x Axis.
SPH is the sphere or “power” (the negative or positive number used to determine the degree of nearsighted or farsightedness), CYL is the cylinder (the negative or positive number used to measure the focusing power of your lens), and Axis refers to the amount of curvature in the lens from 0 to 180 degrees. If you have astigmatism, your prescription should look something like this:
-2.75 +1.00 x 45.
When ordering bifocals or multifocals the distance vision power correction is given with an ADD power e.g.
R -1.00/-1.25 x 55 ADD +2.00
L -1.50/-1.50x165 ADD +2.00
If there are no numbers for CYL, AXIS or ADD in your prescription, do not enter anything in these fields when ordering. When only one number appears for each eye, it is for the sphere power only.