Reading Glasses Strength Calculator

As we age, the crystalline lens inside our eye loses its flexibility—a natural condition called Presbyopia. This makes focusing on close objects difficult, requiring reading glasses or an "ADD" power on your prescription.

Estimated Power by Age

If you have never worn glasses for distance vision, your reading glasses strength is heavily correlated with your age. Use this standard clinical baseline:

Age RangeSuggested Strength
40 - 44 years+0.75 to +1.00 Diopters
45 - 49 years+1.00 to +1.50 Diopters
50 - 54 years+1.50 to +2.00 Diopters
55 - 59 years+2.00 to +2.25 Diopters
60+ years+2.25 to +2.75 Diopters

Calculating from a Distance Prescription

If you already wear distance glasses and want dedicated reading glasses (not progressives), you must algebraically add your "SPH" (Sphere) value to your "ADD" value.

  • Example 1 (Myopia): Distance SPH is -2.00. Your ADD is +1.50. (-2.00) + (+1.50) = -0.50 Reading Glasses.
  • Example 2 (Hyperopia): Distance SPH is +1.00. Your ADD is +2.00. (+1.00) + (+2.00) = +3.00 Reading Glasses.

Need to decode the rest of your numbers? Visit our Prescription Decoding Guide.

Medical Disclaimer

This article is provided for educational and informational purposes only. CorrectLens does not provide medical diagnosis, treatment, or prescription services.

Online vision tests measure visual acuity (clarity of sight) and basic visual performance. They cannot detect eye diseases such as glaucoma, cataracts, macular degeneration, retinal disorders, or neurological conditions.

A comprehensive eye examination performed by a licensed eye care professional is required for medical diagnosis and prescription accuracy.

Medical References