What Strength Reading Glasses Do I Need?

This guide will help you find the reading–glasses strength that works best for most people. The instructions are simple and written at a fifth‑grade reading level.

1. Choose How You Want to Do the Test

Pick one of these two choices:

Option A: Use a Diopter Chart
If you can read this line clearly, your power is + 1.00
If you can read this line clearly, your power is + 1.25
If you can read this line clearly, your power is + 1.50
If you can read this line clearly, your power is + 1.75
If you can read this line clearly, your power is + 2.00
If you can read this line clearly, your power is + 2.25
If you can read this line clearly, your power is + 2.50
If you can read this line clearly, your power is + 2.75
If you can read this line clearly, your power is + 3.25

*For accurate results, print this page at 100% scale.

Option B: Use a Printed Page
  • Use a book, magazine, or any page with normal-sized text.
  • If you pick this option, follow the steps below.
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2. If You Chose Option B: Hold the Page at Arm’s Length

  • This step is only for people using a regular printed page (Option B).
  • Stretch your arm out straight and hold the page in front of you.
  • If the words already look clear, you may only need a low strength.
  • If the words look blurry, go to the next step.
  • If you chose Option A (the printed diopter chart), skip this step and follow the instructions on the chart.

3. Slowly Move the Page Toward Your Face

  • Move the page a little closer, very slowly.
  • Stop moving as soon as the words become clear and easy to read. This moment is important.
  • That is your “clear reading distance.”

4. Measure the Distance

  • Use a ruler or tape measure.
  • Measure from your eyes to the page.
  • Write down the number of centimeters.

5. Use This Simple Formula

Reading Glasses Strength = 100 ÷ distance (cm)
Words become clear at 50 cm → 100 ÷ 50 = +2.00 Words become clear at 40 cm → 100 ÷ 40 = +2.50 Words become clear at 33 cm → 100 ÷ 33 ≈ +3.00

This gives you one universal reading strength. You do not need to test each eye.

6. Tips for Better Results

  • Try the test three times and use your average.
  • Make sure the lighting is bright.
  • Do not test when your eyes feel tired.

7. Important Notes

  • This only gives an estimate.
  • It does not measure astigmatism or full prescriptions.
  • For exact results, visit an eye doctor.