Eye Prescription Explained: A Complete Guide
Post on 10th September 2025
Your eyes are the window to your health and having your eye prescription explained is a crucial part of maintaining optimal vision and long-term eye health.
At Scrivens, with over 85 years of experience as a leading eye care specialist in the UK, we understand that optical eye test prescriptions can seem confusing at first glance. That’s why we’ve created this comprehensive guide to help you decode your results and understand exactly what those numbers and abbreviations mean for your vision.
Whether you’re a first-time glasses wearer or simply want to better understand your existing eye prescription, this guide will help you make informed decisions about your eye care and the lenses that suit you best.
Your Prescription Explained
Sphere (Sph)
The sphere measurement indicates the power of the lens needed to correct your sight. This is one of the most important numbers on your prescription, as it determines whether you’re short-sighted or long-sighted.
A minus power (–) means you are short-sighted, you can see close objects clearly, but distant ones appear blurred.
A positive power (+) means you are long-sighted, meaning you can see distant objects clearly, but close-up objects may appear blurred.
Lens power is measured in 0.25 steps; the higher the number, the stronger the correction required.
Cylinder (Cyl)
Cylinder, often abbreviated as ‘Cyl’, is prescribed to correct astigmatism. Astigmatism occurs when your eye is more curved in one direction than another, like a rugby ball rather than a perfectly round football. This irregularity means light focuses in more than one place on the retina, causing blurred or distorted vision.
Cylinders help to correct astigmatism by providing extra power in one specific area of the lens, improving clarity and sharpness.
Axis
The axis is closely linked to the cylinder measurement, as it indicates the exact angle where the cylindrical correction should be applied. Measured in degrees (1–180), the axis ensures lenses are mounted correctly in your frame, vital for clear vision.
Near Vision Add
This value provides additional power to help you focus on near objects, like reading or using your smartphone. It’s particularly important for people developing presbyopia, the natural, age-related decline in close-up focus.
Intermediate Add
The intermediate add helps with mid-range vision, such as working on a computer. In our increasingly digital world, eye test prescriptions explained often include this value to enhance comfort during long hours of screen use.
Prism
Prisms are prescribed to help your eye muscles work more efficiently and reduce feelings of eye strain or double vision. These specialised corrections help your eyes work together as a team, ensuring that the images from both eyes merge correctly in your brain.
If you’ve been experiencing symptoms like double vision, eye strain or headaches, prism correction might be recommended by your Optometrist to achieve comfortable, clear vision.
Base
The base direction indicates how and where a prism is positioned within a lens to ensure proper alignment. This precision allows the eyes to coordinate correctly, reducing strain and improving visual stability.
Understanding Your Vision Needs
Having your eye prescription explained in the UK doesn’t just help you make sense of numbers; it’s about understanding your unique vision needs. Regular eye tests are vital for maintaining good eye health and can detect problems before symptoms appear.
If you’re struggling with your vision, it can lead to headaches, fatigue, or reduced productivity. With an accurate prescription, your eyes won’t be overworked, helping you enjoy greater comfort and a better quality of life.
Clear, comfortable vision can improve everything from work performance to reading, driving, and everyday activities.
Taking the Next Step
Understanding your eye test prescription explained is just the start of your journey to better vision. At Scrivens, our experienced opticians can offer tailored advice on lens options that suit your lifestyle, whether that’s anti-fatigue, relaxed vision lenses for digital use, or lightweight designs for all-day wear.
If you have any questions about eye prescriptions, lens types, or whether glasses or contact lenses are right for you, speak to your local Scrivens branch. Our team is dedicated to helping you achieve the clearest, most comfortable vision possible.
If you’ve recently received new glasses but still experience headaches or dizziness, contact your optician promptly, small adjustments can make a big difference.
Your vision is precious and having your eye prescription explained is an important step in taking control of your eye health. With regular eye tests, expert guidance, and the right lenses, you can protect your sight for years to come.
For more information or personalised advice, visit your local Scrivens Opticians & Hearing Care branch or explore our website for professional eye care guidance.
If you found this guide helpful, you might also like our post on maintaining healthy vision in the digital age.