First-Time Reading Glasses Buyer? How to Use a Size Chart Without Getting Confused

Buying reading glasses for the first time can be surprisingly confusing. One display talks about +1.00, +1.50, +2.00 as the “size.” Another chart online shows numbers like 52 ▢ 18 – 140 and calls it an eyeglass size chart. Are these the same thing? Which “size” do you actually need?

In this guide we will separate lens strength from frame size, show you how to use both types of charts, and explain how to choose comfortable reading glasses that fit your face.

Two Different “Sizes” You Need to Understand

1. Lens strength – the +1.00, +2.00 numbers

These are diopter powers. They tell you how strong the magnification is for near work. A larger number means stronger reading help. Choosing between +1.00, +1.50 or +2.50 is about how much extra focusing power your eyes need up close.

2. Frame size – the 52 ▢ 18 – 140 type numbers

These numbers are not about magnification. They are measurements in millimeters:

• Lens width (e.g. 52 mm) – how wide each lens is.
• Bridge width (e.g. 18 mm) – the gap over your nose.
• Temple length (e.g. 140 mm) – how long the arms of the frame are.

Together, they tell you how the frame will sit on your face. This is what a true glasses frame size chart or eyeglass size guide explains.

How to Pick a Starting Reading Strength

For most people in their 40s and 50s, the reading power they need increases slowly over time as presbyopia progresses. General suggestions often look like this (always confirm with an eye exam if you are unsure):

• Early 40s – try around +1.00 to +1.25.
• Late 40s – often +1.50 to +1.75.
• 50s and beyond – commonly +2.00 to +2.50 or more.

These are only rough starting points. The best way to choose is:

• Use a reading chart at your normal reading distance.
• Start with the lowest power and move up slowly.
• Pick the lowest strength that lets you read comfortably for 15–20 minutes without strain.

If one eye feels much worse than the other, or if you need very strong reading glasses, it is important to visit an eye doctor for a custom prescription.

How to Use a Glasses Size Chart for Frame Fit

Once you know roughly what reading strength you need, the next step is to choose a frame that actually fits your face. This is where a glasses size chart becomes useful. Instead of guessing, use a step-by-step glasses size guide for your face to understand your frame size category.

In that complete eyeglass frame size chart, you will learn:

• How to find your current frame size numbers on the temple of your old glasses.
• How to match lens width and bridge width to your face width.
• How temple length affects comfort behind your ears.

If you already own glasses that fit well, they are your best reference. Look at the numbers printed inside the arm, then use the eyeglasses size chart to stay in a similar range.

Choosing a Frame Width for Your Face

Frame width is a big part of comfort. If a frame is too narrow, it will pinch. If it is too wide, it will slide down every time you look down to read. By combining the right diopter strength with a suitable frame width, your reading glasses will both improve vision and stay comfortable for long periods.

Common Mistakes to Avoid

• Choosing only by strength. If you grab the first +2.00 you see, it might help you read, but a poor frame size can still cause headaches and pressure.
• Ignoring your reading distance. If you hold your phone close, you may need a different power than if you read at arm’s length.
• Buying a strong pair “just in case.” Too much magnification might make things look big but uncomfortable.

Putting It All Together

Think of your reading glasses in two parts: the lens strength (the + number) and the frame size (the measurements and overall fit). Use a simple reading chart to choose a starting diopter, then rely on a clear eyeglass size chart to find frames that match your face.

Once you understand both “sizes,” the rack of reading glasses in the store – or the product pages online – will stop being confusing and start feeling like a set of clear, organized options.