How to Read Your Glasses Prescription: A Complete UK Guide
How to Read Your Glasses Prescription: A Complete UK Guide
If you've recently had an eye test, you've probably received a prescription filled with abbreviations and numbers that may seem confusing at first glance.
Understanding your prescription can help you make informed decisions when ordering prescription glasses online and ensure you choose the correct lenses for your vision needs.
What Is a Glasses Prescription?
A glasses prescription is a set of measurements used to correct your vision. It tells the laboratory exactly how lenses should be manufactured for each eye.
Your prescription will usually contain separate values for your right eye (RE or OD) and left eye (LE or OS).
Understanding SPH (Sphere)
SPH stands for Sphere and indicates the amount of lens power required to correct short-sightedness or long-sightedness.
A minus (-) value means you are short-sighted (myopic).
A plus (+) value means you are long-sighted (hyperopic).
Examples:
-2.00 = short-sighted
+1.50 = long-sighted
The higher the number, the stronger the prescription.
Understanding CYL (Cylinder)
CYL stands for Cylinder and measures the amount of astigmatism present.
Astigmatism occurs when the front surface of the eye is slightly irregular in shape, causing blurred or distorted vision.
Not everyone will have a CYL value.
Understanding AXIS
AXIS works alongside the CYL measurement.
It tells the lens manufacturer the orientation of your astigmatism correction and is measured between 1 and 180 degrees.
If there is no CYL value, there will usually be no AXIS value.
Understanding Prism
Some prescriptions contain prism measurements.
Prism is used to help align the eyes and reduce issues such as double vision or eye strain.
Not everyone requires prism correction.
What Is Pupillary Distance (PD)?
Pupillary Distance, often shortened to PD, is the distance between the centres of your pupils.
This measurement is important when ordering glasses online because it ensures the optical centre of each lens aligns correctly with your eyes.
An incorrect PD can cause discomfort and reduce visual clarity.
Do I Need All These Measurements to Order Glasses?
Yes. To ensure your glasses provide the best possible vision, you should enter your prescription exactly as it appears on your eye test record.
At SpexNation, our online ordering process guides you through each step to make entering your prescription quick and simple.
Choosing the Right Lens Thickness
Higher prescriptions may benefit from thinner high-index lenses.
Many customers choose:
Standard lenses for lower prescriptions
1.6 lenses for a thinner appearance
1.67 lenses for stronger prescriptions
Choosing the right lens can improve both comfort and appearance.
Final Thoughts
Understanding your glasses prescription doesn't have to be complicated. Once you know what SPH, CYL, AXIS and PD mean, you'll feel much more confident when ordering glasses online.
If you're unsure about any part of your prescription, our team is always happy to help explain your results and recommend suitable lenses.