How to Read Your Contact Lens Prescription (So You Order the Right Lenses)

Ordering contact lenses online is easy once you can read your prescription — but all those numbers and abbreviations can look confusing the first time. This quick guide explains exactly what each part means, so you can order with confidence.

Why your glasses prescription isn’t enough

First, an important point: a glasses prescription is not the same as a contact lens prescription. Contact lenses sit directly on your eye, so they need extra measurements (like base curve and diameter) that glasses don’t. Always order using a current contact lens prescription from your optometrist.

What the abbreviations mean

• OD / Right — your right eye (from the Latin oculus dexter).
• OS / Left — your left eye (oculus sinister).
• PWR or SPH (Power/Sphere) — the strength of the lens. A minus number (e.g. −2.25) means short-sighted; a plus number (e.g. +1.50) means long-sighted.
• BC (Base Curve) — how curved the lens is, to fit the shape of your eye (e.g. 8.6).
• DIA (Diameter) — how wide the lens is across (e.g. 14.2).
• Brand — lenses are fitted to a specific brand; your optometrist notes which one suits you.

If you have astigmatism, you may also see CYL (Cylinder) and AXIS. If you wear multifocal lenses, you may see ADD.

An example

Right (OD): −2.00 / BC 8.6 / DIA 14.2
Left (OS): −2.25 / BC 8.6 / DIA 14.2

This person is mildly short-sighted, slightly more in the left eye, with a standard fit. When ordering, you’d select −2.00 for the right eye and −2.25 for the left.

How to order online step by step

1. Have your current contact lens prescription handy.
2. Choose your lenses (for example, our Clear 1 Day daily lenses).
3. Select the power for each eye from the dropdown menus, matching your prescription exactly.
4. Choose how many boxes you need, add to cart, and check out.
5. We deliver across Australia within 5–6 working days.

Not sure or prescription expired?

Contact lens prescriptions usually need updating every 1–2 years. If yours has expired, book a quick check with your optometrist before ordering — it keeps your eyes healthy and makes sure you get the right fit. If you’re unsure about any number, our team is happy to help: call 1800 317 525.

Try your lenses risk-free

Once you know your prescription, the easiest way to find lenses you love is our 7-day free trial — just $6.95 shipping. Prefer convenience? Subscribe and we’ll deliver automatically so you never run out.

Start your free trial or shop daily, monthly and coloured lenses.

This guide is general information only. Always follow your optometrist’s advice. A valid prescription is required for prescription lenses.