Total Vision Ladera Ranch
Blog Hero

How Do I Know What Strength Reading Glasses I Need?

Book Appointment
A young woman smiling and trying on glasses in a store while being assisted by an optician or optometrist.

Reading glasses are a simple yet powerful tool for those with presbyopia, a natural, age-related vision problem.

Determining the strength you need for reading glasses can be a bit of a challenge. There are many factors to consider. For the most accurate results, visiting an optometrist for an eye exam is always the best option.

If you’re just looking for an approximation, you can use diopter reading test cards or trying different over-the-counter readers to see what works best for you. 

What Is Presbyopia?

Presbyopia is the gradual loss of the ability to see near objects clearly. It’s a natural part of aging that usually starts around the age of 40 and progressively worsens until around your mid-60s. The lens inside your eye is responsible for focusing light onto the retina, creating a clear image.

This lens is normally flexible and can change shape, allowing you to focus on both near and far objects. However, as we age, this lens stiffens and loses its flexibility. Due to this hardening, the lens struggles to adjust focus for close-up tasks like reading.

Reading glasses provide additional focusing power, essentially acting as “external lenses” to compensate for the stiffened lens in your eye. You might need reading glasses if: 

  • You have blurry vision when reading or doing close-up work
  • You’re holding reading materials farther away to see them clearly
  • You experience eye strain, headaches, or fatigue after reading

Understanding Reading Glasses Strength

Reading glasses are available in various strengths and are typically measured in diopters (D). Diopters indicate the optical power of the lens required to correct vision. 

Reading glasses start at +1.00D and increase in 0.25D increments. The strength of reading glasses depends on the degree of presbyopia and your visual requirements. The higher the number needed for prescription glasses, the stronger the lens. 

How to Determine the Right Strength for Readers

Visiting your optometrist is the best way to get an accurate prescription. If you only need minor correction, over-the-counter glasses are a great alternative. For an approximate idea of what strength you need: 

  • Use diopter reading test cards: View or print a card online and hold it at arm’s length. Read down the rows until the text becomes clear. The strength listed next to that line is a ballpark starting point.
  • Try on over-the-counter readers: Choose a store with various strengths and try reading with different pairs. Opt for the pair that provides clear, comfortable vision while avoiding excessive strain. 

Wear Reading Glasses at the Right Distance

Position your reading glasses at the bridge of your nose and make sure they sit comfortably. If your bridge is level with or lower than your pupils, you’ll want to opt for a bridge size between 16 to 18 mm. 

But if your bridge is higher than your pupils, you’re better off with a larger bridge size; around 19 to 21 mm should be just right for you. 

How to Read Your Prescription

Reading a glasses prescription might seem a bit confusing at first, but it’s actually not too tricky once you break it down. 

Your prescription will have terms like “OD” and “OS.” These stand for “oculus dexter” (right eye) and “oculus sinister” (left eye). 

You’ll also see numbers indicating the power of your lenses measured in diopters. Plus (+) signs represent farsightedness, while minus (-) signs indicate nearsightedness. For presbyopia, you’ll see the letters “ADD” followed by a number. This indicates the additional power needed for reading or close-up tasks.

If your prescription is outdated, your eyes may exert more effort than necessary, which can cause blurry vision, eye strain, and neck and shoulder pain. 

Your prescription isn’t merely an intricate array of abbreviations and digits. It provides significant insights into your eyesight. With some basic understanding, interpreting it becomes straightforward.

An optometrist shaking hands with his patient in an optometry office.

Finding Your Perfect Pair of Reading Glasses

Selecting the right strength of reading glasses is important for comfortable and effective vision correction for individuals with presbyopia. 

Your eye doctor is a fantastic resource for understanding what vision correction you need. Contact us at Ladera Ranch Optometry for personalized vision correction and eye health advice. Your next eye exam is waiting for you!

Written by Total Vision

instagram facebook facebook2 pinterest twitter google-plus google linkedin2 yelp youtube phone location calendar share2 link star-full star star-half chevron-right chevron-left chevron-down chevron-up envelope fax