A Simple Guide To Understanding Your Glasses Prescription

Have you ever looked at your glasses prescription and wondered what all the numbers and abbreviations actually mean?

You are not alone.

At ClearSight Domiciliary, many patients ask us to explain their prescription during home eye tests. Understanding your prescription can help you better understand your eyesight, your glasses and any changes in your vision over time.

This guide explains the most common parts of a spectacle prescription in simple everyday language.

What Is A Glasses Prescription?

Your prescription is a set of measurements used to help create lenses that improve your vision.

It tells the optician:

• Whether you are short-sighted or long-sighted

• Whether you have astigmatism

• How strong your lenses need to be

• Whether you need help for reading, distance or both

A prescription usually contains columns labelled:

• SPH

• CYL

• AXIS

• ADD

• PRISM (sometimes)

What Does SPH Mean?

SPH stands for “Sphere”.

This is the main part of your prescription and shows how strong the lens needs to be.

Minus (-) Prescription

A minus prescription means you are short-sighted (myopic).

This means:

• You can usually see nearby objects clearly

• Distant objects may appear blurry

Example:

-1.00

-2.50

-5.00

The larger the number, the stronger the prescription.

Plus (+) Prescription

A plus prescription means you are long-sighted (hyperopic).

This means:

• Distance and near vision may feel strained

• Reading can become difficult

• Eyes may tire more easily

Example:

+1.00

+2.00

+4.00

What Is CYL?

CYL stands for “Cylinder”.

This measures astigmatism.

Astigmatism occurs when the front surface of the eye is shaped slightly unevenly, causing blurred or distorted vision.

Symptoms can include:

• Blurred vision

• Ghosting or shadowing

• Eye strain

• Headaches

• Difficulty driving at night

Not everyone has a CYL value on their prescription.

What Is AXIS?

AXIS works together with the CYL measurement.

It tells the lab the direction of the astigmatism correction.

The AXIS is measured between 1 and 180 degrees.

Although it looks complicated, it is simply positioning information used when making your lenses.

What Does ADD Mean?

ADD stands for “Addition”.

This is usually found on prescriptions for people needing reading support or varifocals.

The ADD value helps with:

• Reading

• Phone use

• Tablets

• Sewing

• Close work

As we age, the eye naturally loses focusing ability. This is called presbyopia and commonly starts from the early to mid-40s.

Distance Glasses vs Reading Glasses

Some patients only need:

• Distance glasses

or

• Reading glasses

Others may require:

• Bifocals

• Varifocals

• Separate pairs for different tasks

At ClearSight Domiciliary, we explain all available options during your home eye test.

Why Does My Prescription Change?

Your eyesight can change over time due to:

• Ageing

• Cataracts

• Diabetes

• Eye strain

• General eye health changes

Small prescription changes are very common and completely normal.

Does A Strong Prescription Mean Poor Eye Health?

Not necessarily.

A strong prescription simply means your eyes require more correction to focus clearly.

Someone with a high prescription can still have healthy eyes.

This is why regular eye examinations are important — eye health and prescription strength are not always linked.

What Are Thin & Lightweight Lenses?

If you have a stronger prescription, you may benefit from thinner lenses such as:

• 1.6 lenses

• 1.67 lenses

• 1.74 lenses

These lenses:

• Reduce thickness

• Improve comfort

• Make glasses lighter

• Improve cosmetic appearance

What Lens Options Are Available?

At ClearSight Domiciliary, we offer:

• Single vision lenses

• Bifocals

• Varifocals

• Anti-glare coatings

• Transitions® lenses

• Thin and lightweight lenses

• NHS and private spectacles

We help patients choose the best option based on:

• Prescription

• Lifestyle

• Comfort

• Budget

Home Eye Tests With ClearSight Domiciliary

ClearSight Domiciliary provides professional home eye tests for housebound patients and care home residents across:

• Greater Manchester

• Lancashire

• Merseyside

• Yorkshire

Our service includes:

• Modern portable equipment

• One-to-one eye care

• Dementia-friendly approach

• Large frame selection

• Personalised recommendations

• Fast spectacle delivery direct to your home or care home

We take the time to explain your prescription clearly and help you understand your eyesight in simple language.

To book a home eye test with ClearSight Domiciliary, contact us today.

ClearSight Domiciliary

0333 335 5350

info@clearsightdomiciliary.com

www.clearsightdomiciliary.co.uk

Professional eyecare, delivered where you need it.