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What Strength Readers Do I Need?

January 11, 2024

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Is it time to pick up a pair of reading glasses? You don’t need a prescription to get high-quality readers with blue-light protection. Let’s look at the advantages of buying affordable reading glasses online and what you need to know to get the right pair of readers.


The answer to that question is probably either “yes” or “eventually.”

Just as it is with almost every part of the body, age affects the eyes. When we’re young, the muscles in our eyes are stronger and better able to flex and bring things into focus. As we age, our eyes can’t flex like they used to. The result, for many of us, is presbyopia, a refractive error that makes it harder to see things up close. It happens to most people in their mid-40s and it’s why people in that age group and above use reading glasses. But premature presbyopia, affecting people under 40, is also common.

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Indications that you have presbyopia and thus need reading glasses include:

Blurry up-close vision. One of the most common ways people learn they need reading glasses is through restaurant menus. Once-readable text is now blurry and more challenging to read. Restaurants are often dimly lit, and reading is more difficult when there’s not enough light. When you hold reading material (such as menus, books, and smartphone text) too close, it gets blurry. That’s a sure sign you need readers!

Eye strain. For many, their eyes begin to feel tired when reading a book or staring at a digital screen for an extended period of time. That’s usually caused by presbyopia; the eyes need to work harder to focus on close objects. One outward sign is that people often squint as their eyes work harder to focus.

Headaches. By reducing eye strain, reading glasses can help with headaches you may get when reading or engaged in up-close work, like sewing.

The halo effect. If you’ve ever seen a fuzzy halo around a lightbulb or oncoming headlights, that’s probably caused by presbyopia. With age, eyes have greater difficulty focusing light into the retina. The result is scattered light that causes fuzzy vision and blurred focus. Reading glasses correct this focusing issue.

Night vision deterioration. It’s a symptom of presbyopia. Night vision deteriorates over time for most of us. Even with lights on, it can be harder to see things up close. People commonly discover this when they can’t see their car dashboard as well as they used to when driving at night.

Eye rubbing. Do you regularly rub your eyes when reading or staring at a screen? That’s a natural reaction to eye strain. The irritation one feels as the eyes work to focus is often an indication of the first stages of presbyopia.

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When people talk about reading glasses in terms of strength, they mean the strength that the lenses offer. This strength, or optical power, is measured as a “diopter,” the unit used to calculate the focusing strength of glasses. The higher the diopter number, the stronger the lens.

Most people who use reading glasses fall into the diopter range of +1.00 to +2.50. Though a diopter for reading glasses can go as high as +4.00. People who use reading glasses in this higher diopter range are often in their 60s and older.

How much does age matter? While not true for everyone, there is a general correlation between age and the strength of the readers you need. The AARP lists this age-to-diopter relationship as: 40 to 43: +1.00 diopter; 44 to 47: +1.25 to +1.50 diopter; 48 to 51: +1.50 to +1.75 diopter; 52 to 55: +1.75 to +2.00 diopter; 56 to 59: +2.00 to +2.25 diopter; 60 to 64: +2.25 to +2.50 diopter; and 65 and over: +2.50 to +3.00 diopter.

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Do you need to get an eye exam from an ophthalmologist to know what kind of reading glasses you need? No. You can easily do an at-home test. One of the most common ways is to download a printable diopter chart. That’s about as simple as it gets! Print the chart. View it 14 inches from your face. Then read the text that gets incrementally larger. The smallest line you can see the most clearly has a corresponding diopter number for your reading glasses.


No. There’s a common misconception that using reading glasses without a prescription will harm your eyes. That they will cause your vision to worsen. But that’s false. Over-the-counter readers are perfectly safe and effective.

The only issue one might face is if they choose the wrong strength. If, for example, you need +1.00 readers and you use +2.50 readers, you might experience eye strain and even headaches. But that’s remedied by choosing the correct strength. So if you don’t know your number, be sure to take an at-home eye test before buying your readers.


No. It’s a myth that you can only wear readers for a certain amount of time. That you need to take a break from using them to give your eyes a rest, lest you risk harming your eyes. Wrong and wrong. For most people, wearing reading glasses all the time isn’t a problem. This is largely because most readers have relatively low focusing power. Often, over-the-counter readers only go up to +2.50 diopters. Experts advise that if your reading needs are +2.75 diopters and higher, it’s a good idea to get prescription lenses.

One can, however, wear readers in the wrong situations. Readers are designed to enhance up-close vision. So wearing readers while doing things like driving or other everyday activities in which we use a wider scope of vision is a bad idea. You might even get a headache wearing readers in inappropriate situations.

If you’re looking for inexpensive reading glasses, you can’t go wrong with Knockaround readers! Check out our selection of stylish readers with blue light filtering lenses today.

Written for Knockaround by William McCleary

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