How to read your eyeglasses prescription
At first glance your eyeglasses prescriptions might look like a bunch of confusing numbers, symbols and abbreviations. Here is a guide to help you understand this information.
Your prescription might look like this:
(SPH) (CYL) (AXIS)
(O.D.) R: -2.50 / -0.50 x 100
(O.S.) L: -1.50 / -1.00 x 52
(ADD + 2.50)
Reading your prescription:
- O.D. & O.S. tells you which eye the prescription refers to. “O.D.” is the right eye and “O.S.” is the left eye.
- SPH: a nearsighted or farsighted “spherical error”. A “-“means that the prescription is nearsighted, A ”+” means that your prescription is farsighted. The higher the number, the stronger your prescription.
- CYL & AXIS: these numbers describe your astigmatism. The “CYL” number shows the severity of the astigmatism. Axis indicates which way the astigmatism is oriented.
- ADD: this number is only used for bifocals and is added to the sphere prescription to get the near vision prescription.
- PD: is the pupil distance. If you don’t not know your P.D. than go to learn how to measure your Pupil Distance.