Reading Glasses Guide — Strength & How to Choose
Reading Glasses Guide — Strength & How to Choose
If you find yourself holding books or your phone further away to read, you’re probably entering the early stages of presbyopia — the natural age-related change in your eye’s ability to focus on close objects. Reading glasses are the simplest fix.
This guide explains how reading-glass strengths work, how to choose the right one for you, and when to consider an alternative.
How reading-glass strength works
Reading-glass strength is measured in dioptres, written as a positive number (e.g. +1.50). The higher the number, the stronger the magnification.
You’ll find reading glasses sold in 0.25 increments, from +0.50 (very mild) up to +3.50 (very strong). Most adults need somewhere between +1.00 and +2.50 by age 60.
Reading strength by age — typical guide
This is a general guide, not a substitute for a sight test. Your actual prescription depends on your eyes.
| Age | Typical reading strength |
|---|---|
| 40–44 | +0.75 to +1.00 |
| 45–49 | +1.00 to +1.50 |
| 50–54 | +1.50 to +2.00 |
| 55–59 | +2.00 to +2.25 |
| 60+ | +2.25 to +2.75 |
Reading-strength change typically slows or stops by your mid-60s.
Off-the-shelf vs prescription reading glasses
Off-the-shelf readers from a chemist are made with the same correction in both eyes — useful as a backup pair, but rarely ideal. Most adults have slightly different prescriptions in each eye, and many have astigmatism that off-the-shelf readers can’t correct.
Prescription reading glasses are made to your exact specification in both eyes, including any astigmatism correction and your true pupillary distance. They’re sharper, more comfortable, and reduce eye strain over long reading sessions.
Reading glasses vs varifocals
If you only need correction for close-up tasks, single-vision reading glasses are the simplest option — they sit on your face only when you’re reading.
If you also need distance correction (e.g. for driving or watching TV), varifocals combine both prescriptions into a single lens so you don’t have to switch between two pairs.
Frequently asked questions
Can I just buy off-the-shelf readers?
You can, but they won’t correct any difference between your two eyes or any astigmatism. For occasional reading they’re fine. For daily use, prescription reading glasses are more comfortable.
How do I know if I need readers or varifocals?
If you only need help with close tasks, readers. If you also need help with distance vision, varifocals or two separate pairs.
Will my reading prescription get stronger over time?
Usually yes, gradually, until your mid-60s. After that it tends to stabilise.
Can I order reading glasses online without a prescription?
Yes for non-prescription off-the-shelf readers. For tailored prescription readers we recommend a recent sight test — your optician will give you the reading addition (Add) value.
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