Prescription guide

Your prescription is a short table of numbers. Here's what each part means so you can enter it with confidence.

How to read your prescription

• SPH (Sphere) — the main lens power. A minus (–) value means short-sighted; a plus (+) means long-sighted.
• CYL (Cylinder) — the amount of astigmatism correction. May be blank if you don't have any.
• AXIS — the angle (1–180) for the CYL. Only appears if you have a CYL value.
• ADD (Addition) — extra power for reading, used for reading or varifocal lenses.
• PRISM / BASE — only on some prescriptions; enter it if it's there.

PD (Pupillary Distance)

PD is the distance between the centres of your pupils, in millimetres — it makes sure the lenses line up with your eyes. It's often on your prescription; if not, you can ask your optician, or measure it at home with a ruler in the mirror. A typical adult PD is 54–74mm. ‹add your PD help guide if you have one›

Entering it when you order

At checkout you can type your values in, or upload a clear photo of your prescription. We review every order before glazing and will contact you if anything needs checking.

A quick note

Prescriptions are usually valid for up to two years. If yours is older, or your vision has changed, it's worth booking a fresh eye test before ordering.