If you’ve ever looked at your glasses prescription and thought it was written in code, you’re not alone. Between the numbers, abbreviations, and unfamiliar terms, it can feel more like deciphering a secret message than shopping for eyewear.

At Eyesports, we want you to feel confident when ordering glasses, whether they’re prescription sports goggles, sunglasses, or everyday eyewear. Here’s a simple guide to help you understand what all those numbers and letters mean.


The Basics: Right Eye, Left Eye

Your prescription will usually have two main columns:

  • OD (Oculus Dexter) – Right Eye

  • OS (Oculus Sinister) – Left Eye

Sometimes you’ll just see R and L instead.


SPH (Sphere) – Shortsighted or longsighted

The SPH number tells you if you’re:

  • Short-sighted/nearsighted/myopic – difficulty seeing far away moreso than close, shown with a minus (-) sign.

  • Long-sighted/farsighted/hyperopic – difficulty seeing up close moreso than far away, shown with a plus (+) sign.

The bigger the number (e.g. -4.50 or +3.00), the stronger the prescription.


CYL (Cylinder) & Axis – Astigmatism

If you have astigmatism (an irregularly shaped cornea or lens), you’ll see numbers in the CYL column. Astigmatism can cause blur at all distances.

  • CYL tells us the lens power needed to correct it.

  • Axis (a number from 1–180) tells us the direction of the correction.


ADD – For Reading or Multifocals

ADD is short for “Addition” and appears when you need extra magnification for close-up work, often due to presbyopia (age-related difficulty focusing up close, usually starting in mid-40s), and sometimes due to eyestrain. 

  • The ADD value is the extra power added to the lower part of your lenses for reading.

  • If you see an ADD value, you may choose single vision reading glasses or multifocals or bifocals


PD – Pupillary Distance

Your PD (Pupillary Distance) is the measurement in millimetres between the centres of your pupils. It’s crucial for ensuring that your lenses are positioned correctly in your frames.

  • If your PD is wrong, you might experience blurry vision, eye strain, or headaches.

  • Distance vs Near PD: Distance PD is measured when you look straight ahead and is used for distance or general-purpose glasses. Near PD is slightly smaller and is measured when you’re focusing on something close, like for reading glasses.

  • Your optometrist will usually note it on your prescription, but if not, it can be measured in-store or even at home with a ruler and mirror. See here for instructions

  • Adults usually have a PD between 54–74mm, kids between 43–58mm.

Single Vision (SV) vs Multifocal (MF)

  • Single Vision (SV) lenses have the same prescription across the whole lens, ideal for one visual task (distance, computer, or reading).

  • Multifocal (MF) lenses have a gradual change in power from top to bottom, letting you see near, intermediate, and far without switching glasses.


Multifocals (MF) vs Bifocals (BF)

  • Bifocals have two distinct zones - distance on top, reading on the bottom, with a visible line between them.

  • Multifocals (also called progressives) blend the zones for a seamless look and more natural vision transitions.


SVD vs SVN

You might also see:

  • SVD – Single Vision Distance (used for driving, sports, general wear). If you have a near add, these may be blurry for close up tasks. 

  • SVN – Single Vision Near (for reading or close work only). If you have a near add, these will be blurry for distance.


Need Help Deciding?

If your prescription looks complicated or you’re unsure whether to go for SV, MF, or BF, feel free to give us a call. At Eyesports, we’re proudly Australian-owned, and when you ring us you’ll speak to a real person. We also have a local optometrist on site once a week for more complicated prescriptions or more specialised prescription sports eyewear.

Al our prescription products are also covered by all Australian health funds, just request an itemised receipt to make a claim.


Ready to Order?

Now that you know how to read your prescription, you can order your eyewear with confidence. Explore our range of prescription sports goggles, sunglasses, and performance eyewear - all fitted in our Aussie lab for precision and fast turnaround.