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:

Example 1:

Example 2:

              (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.