How to read your prescription

If you already have a prescription from your optician or eye care professional, you’re ready to order. To help you enter your prescription correctly online, we’ve prepared a simple guide explaining each measurement and term.

How to read your prescription

How to transfer prescription values to your order

Single vision prescription
A standard prescription includes the values shown below for the right and left eye separately. For single vision lenses, please transfer the values using the example below.
Prescription guide

Glossary

R / OD

Right Eye

L / OS

Left Eye

SPH (Sphere)

Sphere power is a core part of your prescription. SPH (+) usually indicates difficulty seeing nearby objects, while SPH (-) indicates distance vision correction. Higher diopter values mean a stronger prescription and usually increase in 0.25 steps. If no power is required, it may appear as 0.00, Plano, or Plain.

CYL (Cylinder)

Cylinder power indicates astigmatism or persistent blurred vision. Larger numbers mean stronger correction and are usually listed in 0.25 diopter steps. If astigmatism correction is not needed, this value may be left blank.

Axis

Axis is measured from 0 to 180 degrees and indicates the direction of astigmatism. It must be used together with CYL. If there is no astigmatism, this value is not required. 0 and 180 degrees are considered the same direction.

PD (Pupillary Distance)

Pupillary distance is measured in millimeters (mm) and may be recorded as separate right/left values or as a combined total. This value determines the optical center placement of the lenses in the frame, so a large error can cause discomfort or dizziness.