Optics Mag is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Read more.

What Strength Reading Glasses Do I Need? How to Tell!

Last Updated on

woman using reading eye glasses

As you age, you will likely need reading glasses to see items up close. The reason for this is that humans experience a condition called presbyopia with age. This condition makes it more difficult to focus on items up close due to light reflection issues. Reading glasses can correct this issue.

In order for reading glasses to help you, you have to get the proper strength. If you get the wrong strength of glasses, the glasses will likely not correct your vision much. What strength is best?

If you are considering reading glasses but do not know what strength you need, you have come to the right place. This article will help you figure out what strength reading glasses you need.

Understanding Reading Glasses Strength

To know what strength reading glasses you need, you need to understand the strength of reading glasses and what they mean.

As you probably figured, the strength of reading glasses tells you the strength level that the lenses provide. The rating strength is sometimes referred to as “reading power” or “diopter.” Whenever you are looking at reading glasses, the reading power will be denoted with “+” followed by a number.

Over-the-counter reading glasses offer reading power that starts at +1.00. The strength will then increase in +0.25 increments. The higher the number, the more powerful the lens is.

woman using reading eye glasses
Image By: Piqsels

How to Determine What Strength Reading Glasses You Need

Once you understand the basics of reading glasses strength, you can determine which strength you need.

If You Already Have Reading Glasses

If you already have reading glasses, the process of finding your recommended strength is pretty easy. Put on your reading glasses and look at a book. If you have to hold the book far away, you need a stronger pair. In the case that you can read perfectly fine, you have the right strength.

young man wearing eyeglasses studying in dim light
Image By: ACasualPenguin, Pixabay

Diopter Reading Test

If you need a new strength or have never worn reading glasses before, the easiest way to figure out your needed strength is with the diopter reading test card method. This method is easy and straightforward. Find a diopter chart and hang it 14 inches away from your face.

First, look at the chart without your glasses. Begin by reading from the top row. If you can’t read this line, continue moving down until you find a line that you can read. Next to that line, you will find the recommended strength you need.

Trial and Error

As you age, your eyesight will change, which means the strength you needed before may not be relevant anymore. For this reason, be prepared to get new reading glasses strength through trial and error. As soon as you notice that you have to work harder to read a book, begin looking for new reading glasses.

woman choosing eye glasses
Image Credit: George Rudy, Shutterstock

Summing Up

If you are having trouble seeing items up close, it may be time for reading glasses. Although reading glasses strength may seem intimidating at first, they are pretty easy. You can determine what strength reading glasses you need by using the diopter method or simply trying out different reading glasses at a local store.

In the case that you are still having trouble reading even when wearing glasses, it may be time to see an optometrist. An optometrist will be able to pinpoint the issue and get you the prescription glasses you need.

Featured Image Credit: Image Point Fr, Shutterstock

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.