How to Read Your Prescription

How to read your prescription

Your prescription looks like a small table of numbers. Here's what each part means so you can enter it correctly in our lens builder.

The columns

• OD (Right eye) — sometimes written "R".
• OS (Left eye) — sometimes written "L".
• SPH (Sphere) — the main lens power. A minus value (−) means short-sighted; a plus value (+) means long-sighted.
• CYL (Cylinder) — the amount of astigmatism correction. Leave blank if your prescription has none.
• AXIS — a number from 1 to 180 that goes with CYL. Only needed if you have a CYL value.
• PD (Pupillary Distance) — the distance between the centres of your pupils, in millimetres. Usually between 54 and 74.

Entering it with us

Copy each value exactly, including the + or − sign. For example, an SPH of −1.75 should be entered as −1.75, not 1.75. If a box on your prescription is empty, leave ours empty too.

Don't have your PD?

Your optometrist can add it, or you can measure it at home with a ruler and a mirror. If you're unsure, choose "send my prescription later" and we'll confirm it with you.

This guide is general information, not medical advice. Always order lenses from a current, valid prescription.