What Strength Reading Glasses Do I Need?

Reading glasses come in all sizes, styles and strengths. You can buy them in almost any drug store, grocery store or department store.

To calculate how powerful you need your reading glasses to be, you should know definitively how poor — or how strong — your near vision is.

See an eye doctor for an accurate measurement of your vision before you shop for new reading glasses.

What Are the Reading Glass Strength Options?

As you age, you are likely to encounter issues with your vision. Luckily, wearing the right strength reading glasses can solve this problem. 

You measure the strength of reading glasses in diopters. For people with presbyopia, the power of their reading glasses typically ranges from +1 to +4 in increments of 0.5. Such as: 

• +1.00
• +1.50
• +2.00
• +2.50
• +3.00
• +3.50
• +4.00

The higher the number, the stronger the lens. A diopter of +3.00 or more means you need glasses of greater magnifying power than someone who has a diopter of +1, +1.5, +2 and +2.5.

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What to Consider When Choosing a Reading Glass Lens Strength

Here are things to consider when you pick the strength of your reading glasses:

• Age: In your mid-forties, you will likely use low-power reading glasses. But as you get to your sixties, you may need stronger reading glasses of +2.50 diopters or more.
• Power of the reading glasses: Always choose glasses whose strength coincides with your diopter’s measurement.
• Sun protection: You probably won’t use your laptop outdoors much, but you probably will use your mobile devices (phones and tablets). In addition, will you be in a park, sitting on a bench or laying on a beach reading a book? If so, you will likely benefit from a polarized reading lens or else from reading glasses that are small enough that a large pair of non-prescription sunglasses can fit over the readers.
• Neck straps: Will you use your readers most of the day or all day but not full-time? If so, you may want a neck strap or a neck chain for your glasses so that when you take them off they can hand from your neck and be accessible quickly.

Reading Glasses Strength Tests

There are a couple of home and online tests you can conduct to find the suitable strength for your reading glasses. But you still will need a comprehensive eye exam from the eye doctor to get a detailed prescription for eyeglasses.

Possible tests include:

• Diopter test
• Online vision test
• Near vision test

Diopter Test

A diopter test is a common eye exam that uses diopter charts with different-sized words in rows. Follow this procedure when using the diopter test:

• Hold the diopter chart 1.2 feet (14 inches) away from your eyes.
• Start by reading words on the uppermost row of the chart without using glasses.
• If the letters in the uppermost chart look blurry, keep reading as you go down the chart. Do this until you find those that you can read clearly.
• Once you’ve identified the clear letters, look at the adjacent diopter number printed at the corner of the row.
• This number shows the strength of the reading glasses suitable for your eyes.

Online Vision Test

Some companies conduct online vision tests using apps. The tests are more or less the same as those done in the eye doctor’s clinic, but they are conducted virtually. If you decide to do the online test, ensure to take it from a company approved by U.S. Food and Drug Administration (FDA).

Near Vision Test

Near vision testing is a common exam meant for people with presbyopia. You do it using the continuous text near the vision card. This card measures your reading capabilities while holding the card at a certain distance. 

Hold the card 14 to 18 inches away when taking the test. Try to read the letters with the smallest text size first. If you already have reading glasses, wear them during the test. Perform the test for each eye separately.

Reading Glass Strength for Books vs. Screens

As there are glasses for reading books, there are also glasses you wear when using electronic devices, known as computer glasses. Although you can use your regular glasses to view computer screens, they don’t serve the same purpose as computer glasses. 

Reading glasses enable you to focus on objects 14 inches away (the average reading distance when holding a book). But when using a computer, you view it from a distance farther than your reading glasses can correct. 

In addition, computers produce blue light. Computer glasses have a special coating that blocks this blue light from reaching your eyes, but reading glasses don’t.

Other Things to Consider When Choosing Reading Glasses

Lens Design

There are different categories of reading glasses:

• Single vision: They have a fixed focus, either near or distant vision. It would be best to choose single vision glasses that correct near vision for reading glasses. That means you can read a book while holding it in a normal reading position.
• Bifocal lens: These glasses enable you to read with the bottom section of the lens and focus on distant objects with the top section. You thus don’t need to remove the glasses when viewing things that are far away.
• Trifocal lens: reading glasses with this lens corrects both near, middle, and distant vision.

Custom and Ready-Made Glasses

Ready-made glasses are cheaper, and you can purchase them from the drugstore. However, there’s no telling if they are right for you. You acquire custom-made glasses after an eyeglass prescription from the eye doctor.

Frames for Your Reading Glasses

You can decide to choose metal or plastic frames for your eyeglasses. Plastic frames come in a plethora of colors but are susceptible to breakage. On the other hand, metal frames are more resistant to wear and tear. Always choose frames that fit perfectly with your ears, face, and nose bridge.

Benefits of Reading Glasses

Apart from improving your reading abilities, here are the other benefits of wearing reading glasses:

• They protect your eyes from direct wind and debris.
• Some are fashionable.
• It enables you to do other activities, such as driving.
• Helps avoid uncomfortable symptoms such as eye strain.
• They are convenient and comfortable to use.

References

1. Do blue-light-blocking glasses work? (April 2021). Baylor College of Medicine.

2. Why Can’t I See the Computer Clearly With My Bifocals? (December 2020). Cleveland Clinic.

3. Online and remote eye exams. (October 2020). Consumer Ed.

4. How can presbyopia be corrected? (June 2020). InformedHealth.org.

5. Eyeglasses for Refractive Errors. (July 2019). National Eye Institute.

6. Reading charts in ophthalmology. (April 2017). Graefe’s Archive for Clinical and Experimental Ophthalmology.

7. Near vision examinations: Do we need homologated near-vision charts? (November 2016). Eye and Vision. 

8. How to prescribe spectacles for presbyopia. (March 2006). Community Eye Health Journal. 

9. The efficacy of computer glasses in reduction of computer worker symptoms. (April 2002). Optometry.