What strength reading glasses do I need?
By See Better · Updated · 4 min read
The short answer
Most people start with reading glasses of about +1.00 in their early to mid 40s and need roughly +2.50 by their 60s. Choose the weakest power that lets you read comfortably at about 40 cm. Ready-made readers only suit people whose two eyes are similar and who have little astigmatism.
Key points
- Typical strengths: +1.00 around age 40 to 45, rising to about +2.50 by 60.
- Pick the lowest power that makes small print comfortable at your normal reading distance.
- Ready-made readers have the same power in both lenses and no astigmatism correction.
- The need for reading glasses is also your cue for an eye health check.
Reading glasses strength by age
The power of reading glasses is measured in dioptres and goes up in steps of 0.25. Because the eye's ability to focus up close fades at a fairly predictable rate, age gives a reasonable first guess:
| Age | Typical reading strength |
|---|---|
| 40 to 44 | +0.75 to +1.00 |
| 45 to 49 | +1.00 to +1.50 |
| 50 to 54 | +1.50 to +2.00 |
| 55 to 59 | +2.00 to +2.25 |
| 60 and over | +2.25 to +2.75 |
Treat this as a starting point only. It assumes your distance vision is good without glasses. If you are a little long-sighted you will need more, and if you are short-sighted you may need less or none at all, which is why many short-sighted people simply take their glasses off to read.
How to test a pair in the shop
- Hold a book, a medicine box or your phone at the distance where you normally read. For most people that is about 35 to 40 cm.
- Start with the lowest power on the rack and work upwards.
- Stop at the first pair that makes small print clear and comfortable. Stronger is not better.
- Check that you can also see at your usual working distance. If you have to pull the page closer than is natural, the glasses are too strong.
Too strong a pair forces you to hold things very close and can cause headaches. Too weak, and you will still be stretching your arms.
Reading distance and screen distance are different
A computer screen sits further away than a book, usually 50 to 70 cm. It needs less power, often about half your reading addition. If your +2.00 readers make the laptop blurry unless you lean in, that is the reason. People who do a lot of screen work often do better with a dedicated pair set for screen distance, or with multifocal lenses that cover every distance.
The limits of ready-made readers
Pharmacy or supermarket readers are inexpensive and handy as a spare pair. They are also a compromise:
- Both lenses have the same power. Most people's eyes differ a little, and some differ a lot.
- They do not correct astigmatism. If you have astigmatism, print will never be quite sharp.
- The lens centres are set for an average face. If your eyes are closer together or further apart than average, you can get eye strain.
- Lens quality varies.
If ready-made readers give you headaches, tired eyes or one eye that always seems worse than the other, you need a pair made to your own prescription.
Why you should still have an eye test
Needing reading glasses for the first time is completely normal. It is called presbyopia and it happens to everyone. It also arrives at the age when the risk of conditions such as glaucoma begins to rise. These cause no symptoms at first, and a pair of readers from the pharmacy will not find them.
An eye test at this point does two things: it gives you the exact power each eye needs, and it checks the health of your eyes. If your near vision has changed quickly, or one eye has changed much more than the other, do not self-prescribe. Have it looked at.
Will reading glasses make my eyes worse?
No. This is one of the most common worries, and it is a myth. Your near focus weakens with age whether or not you wear glasses. Reading glasses do not speed that up. They simply stop you struggling in the meantime. You will need a slightly stronger pair every few years until your mid 60s, when the change levels off.
Frequently asked questions
What strength reading glasses do I need at 50?
Most people aged 50 need between +1.50 and +2.00 for reading, assuming their distance vision is good. An eye test will give you the exact figure for each eye.
Is it bad to wear reading glasses that are too strong?
It will not damage your eyes, but it is uncomfortable. Glasses that are too strong make you hold things very close and can cause eye strain and headaches. Choose the weakest power that gives clear, comfortable reading.
Can I wear reading glasses all day?
You can wear them for close work for as long as you like, but they will blur your distance vision, so they are not suitable for walking around or driving. If you need both distances all day, ask about bifocals or multifocals.
What is the difference between reading glasses and prescription glasses?
Ready-made reading glasses have the same simple magnifying power in both lenses. Prescription reading glasses are made for each eye separately, correct astigmatism, and are centred to match the distance between your pupils.
This article is general information and is not a diagnosis or a substitute for an eye examination. If you are worried about your eyes or your sight, see an optometrist or a doctor. Sudden loss of vision, eye injuries and severe eye pain are emergencies.
