What Does a Glasses Prescription Look Like?
A standard Australian glasses prescription will have two rows - one for each eye -and several columns. It looks something like this:
| Eye | SPH | CYL | AXIS | ADD | PRISM |
|---|---|---|---|---|---|
| R (Right / OD) | -2.25 | -0.75 | 180 | ||
| L (Left / OS) | -1.75 | -0.50 | 165 |
Let's break down what each column means.
Understanding Each Part of Your Prescription
SPH - Sphere
This is the main lens power needed to correct your vision. It's measured in dioptres (D).
- A minus (–) number means you're short-sighted (myopic) - you can see close up but struggle at distance
- A plus (+) number means you're long-sighted (hyperopic) - you can see far but struggle up close
- The larger the number (ignoring the sign), the stronger the prescription
Example: –3.00 is a stronger short-sighted prescription than –1.25
CYL - Cylinder
This indicates astigmatism - an irregularity in the curvature of your eye. Not everyone has astigmatism; if this column is blank or reads "DS" (Dioptre Sphere), you don't have it.
- Can be a plus or minus number
- Works together with the AXIS value
AXIS
Only relevant if you have a CYL (astigmatism) value. The Axis is a number between 1 and 180 that tells the lens maker at what angle to position the cylindrical correction.
ADD - Addition
This appears on prescriptions for reading glasses, bifocals, or progressive/multifocal lenses. It represents the extra magnifying power added to the bottom portion of the lens for reading.
- Always a positive number, typically between +0.75 and +3.50
- If you have an ADD value, you likely need bifocal or progressive lenses
PRISM
Less common. Prism correction is used when your eyes don't work together properly (binocular vision issues). If this column is blank, you don't need it. If your script includes Prisms, contact us for a personalised quote.
What Is PD (Pupillary Distance)?
Your PD is the distance in millimetres between the centres of your pupils. It's not always on your prescription as some optometrists don't include it, but it's essential for ordering prescription glasses online.
You may have:
- A single PD (e.g. 64mm) - the total distance across both eyes
- A dual PD (e.g. 32/32 or 31.5/32.5) - each eye measured separately from the centre of the nose
You can measure it at home using a ruler and a mirror, or ask your optometrist. We also have a full guide to measuring your PD on our website.
Common Prescription Abbreviations
| Abbreviation | Meaning |
|---|---|
| OD or R | Right eye (from Latin oculus dexter) |
| OS or L | Left eye (from Latin oculus sinister) |
| OU | Both eyes |
| SPH or S | Sphere |
| CYL or C | Cylinder |
| DS | Dioptre Sphere (no astigmatism) |
| ADD | Addition (for reading/multifocal) |
| D | Dioptres (unit of lens power) |
| PD | Pupillary Distance |
What Type of Lens Do I Need?
Once you understand your prescription, choose your lens type below. We have various thin high index options available that can make your lenses ligher and cosmetically more pleasing.
| Prescription Type | Lens You Need |
|---|---|
| SPH only, no ADD | Single Vision |
| SPH + CYL/AXIS, no ADD | Single Vision (with astigmatism correction) |
| SPH + ADD value | Progressive, Bifocal, or Reading glasses |
| Large minus SPH (–4.00 or more) | Consider high-index (thinner) lenses |
| Large plus SPH (+3.00 or more) | Consider high-index (thinner) lenses |
How Long Is a Prescription Valid?
In Australia, a glasses prescription is typically valid for 2 years from the date of issue. Some optometrists may note a shorter validity on the prescription itself - always check.
If your prescription is expired, you'll need a new eye test before ordering new glasses.
Can I Order Glasses Online With My Prescription?
Yes - and it's easy. At Optically you can:
- Enter your prescription manually at checkout OR
- Upload a photo of your prescription OR
- Email it to us after placing your order
Our team checks every prescription before glazing your lenses, so if anything looks unclear or unusual, we'll contact you before proceeding.
Frequently Asked Questions
My prescription has a minus CYL. Is that normal?
Yes - prescriptions can be written in either minus or plus cylinder format. Both are correct; they're just different notations for the same correction. Opticians can convert between them.
What if my two eyes have very different prescriptions?
This is called anisometropia and is common. Your prescription will simply show different values for each eye. High-index (thin) lenses are usually recommended in this case.
My prescription just says "Plano" or "0.00" - what does that mean?
Plano means no correction is needed for that eye for distance. You may still have an ADD value for reading.
Can children's prescriptions be entered online too?
Yes. Enter the values exactly as written. If you're unsure about any part of a child's prescription, feel free to contact us before ordering.
Do I need a different prescription for glasses vs contact lenses?
Yes - they're different. A contact lens prescription includes additional measurements (base curve, diameter) and the power may differ slightly. Don't use a contact lens prescription to order glasses.
Ready to Order?
Now that you understand your prescription, ordering glasses online is simple. Optically offers prescription glasses from just $19 including lenses, with many frame options that can possibly dispatch from our Sydney optical lab within 72 hours. If you are in a hurry for glasses, please contact our friendly customer service team by text, call or email to explore suitable frame and lens options and avail of our Express Service,
