How to Read Your Glasses Prescription
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Buy glasses online with confidence — here’s the easiest way to understand your prescription.
Ordering glasses online can feel confusing but we break everything down so its easy, clear, and stress-free. Here’s your friendly guide to understanding exactly what your optician has written, so you can choose the perfect lenses with complete confidence.
Your Prescription Explained
Your glasses prescription is basically the formula for your perfect vision. It tells us how to make lenses that match your eyes — whether you need help with distance, reading, or both.
Here are the parts you’ll see most often:
1. SPH (Sphere): Your Main Strength
- A minus (–) means you’re nearsighted
- A plus (+) means you’re farsighted
This is the part most people recognise-your main lens strength.
2. CYL + AXIS: Astigmatism (If You Have It)
If your prescription includes CYL and AXIS, it simply means your eye has a slightly different shape and needs a little extra correction.
- CYL = the amount
- AXIS = the direction
If these boxes are blank, you don’t have astigmatism.
3. ADD: Extra Help for Reading
If you wear varifocals, bifocals or reading glasses, you’ll see an ADD number.
This gives you that close-up “boost” for reading, screens, or detailed work.
4. PRISM: Less Common
If PRISM is on your prescription, your optician is correcting eye alignment or double vision. Most people won’t have this.
5. PD: (Pupillary Distance)
Your PD tells us how far apart your eyes are.
We need this to make sure your lenses sit perfectly in the frame, especially when ordering online. If it isn’t written on your prescription (which is very common), you can use our PD Calculator
Example Prescription:
Right Eye: SPH –1.50, CYL –0.50, AXIS 90, ADD +2.25
Left Eye: SPH –1.25, ADD +2.25
PD: 62mm
In simple terms, this means both eyes need distance correction, the right eye has a touch of astigmatism, and both need extra help for reading.
When to Ask for Help:
Prescriptions can feel like a foreign language! You should always ask for help if:
- Your PD isn’t listed or you’re unsure how to measure it.
- There are values you don’t recognise (or something looks “off”).
- You want advice on which lenses or coatings are best for your prescription.
- You need style help picking the perfect frame.
Have questions or need advice? Contact us and we’ll walk you through it, step by step. Your comfort and clarity are always our priority!
FAQs:
Can I use my NHS prescription to order glasses online?
Absolutely! Just upload your prescription at checkout, or email it to us if you have questions.
What if my prescription is over a year old?
It’s best to have an up-to-date prescription (within the last 2 years) for accuracy and comfort.
What if I don’t know my PD?
No worries! We have a free PD Calculator or you can ask your optician
Do you offer help choosing frames for strong prescriptions?
Yes! Our team can recommend styles that suit any prescription strength and keep you looking great.
If you’re unsure whether you need prescription glasses at all, this guide explains the difference.
Still stuck? Don’t worry—drop us a message and we’ll help you decode your prescription, no magnifying glass required!
Ready to Order? Shop with Confidence!
Browse our collection of stylish, affordable frames here Mens, Womens, Unisex, and upload your prescription at checkout.
