Picture this: you go to your favorite restaurant, grab a corner seat, and pick up the menu. But as you browse through it, you notice the text seems blurry, meaning you have to hold the menu up close to see the fine print. Sound familiar? Well, this could mean you are a candidate for reading glasses. For starters, talking to an optometrist would be your best bet if you need reading glasses for men.

All the same, how can you tell that you need reading glasses? Here are some tell-tale signs to keep an eye out for:

Frequent headaches due to eye strain
Age is doing a number on you – reading power tends to decrease with age, starting at 40.
You’re using larger text when writing by hand or on your computer.

If you’re searching for a place to start, we’ve prepared a guide to help you figure out the reading power of your lenses or their magnification. Here are a few options you may consider:

1. Let an Expert Do Their Thing

Well, if you’ve ever been told you need reading glasses, you may have wondered how the optometrist determined the strength of your lenses. The truth is, a few steps go into it.

First, the optometrist measures the distance from your pupils to the corneas (the clear front surfaces of your eyes). This is called the “interpupillary distance” or IPD. Then, they’ll measure the curvature of your corneas. This helps them calculate the power of your reading glasses based on the refractive power of your eyes.

Ultimately, they consider any presbyopia (age-related farsightedness) you may have. Then, they can determine the strength of your reading glasses to prescribe. Alternatively, if you need non-prescription readers, you can use the following approaches to find the ideal strength or reading glasses:

2. Use a Diopter Reading Test Card

I know it’s a mouthful, but the diopter reading test card is a chart with rows of different-sized letters to help determine the best reading strength. You can find a printable diopter chart online. It’s also advisable to use the printed version of the card for best results.

To use the card, hold it at least 14 inches from your face – although it’s preferable to hang it on a wall. Expert tip: if you already have a pair of reading glasses, remove them first. Then, try to read the text at the top. Chances are you won’t read the top line clearly, as it’s usually the smallest. Proceed down the card until you get to the text you can read without straining your eyes.

How Do I Know What Strength Reading Glasses to Get?

The number on that line corresponds to the power of your reading glasses. For instance, if the smallest line you can read is a 3, you would need a 3 diopter lens. Here are pointers on the magnification that might work for your situation:

+0.50 Diopter glasses: if you need help with slightly blurry vision, these may be the right glasses.
+1.00 Diopter glasses: Ideal if you struggle to read street signs or the print in magazines.
+1.50 Reading glasses: if the small print becomes difficult to see, +1.50 diopter lenses may improve your vision.

The largest text strength on the test card is usually +3.25. Some people may need to go even higher than that. If so, you’ll need to visit an optometrist to get a prescription for stronger reading glasses.

3. Try Various Magnifications.

What do you do if you find a pair of pants and want to ensure it fits you? You try it on, right? Well, you can try out various prescription lenses to find an ideal pair of reading glasses.

Generally, the reading magnification or power increases by 0.25 diopters, although it’s not uncommon to see a diopter chart with 0.5 increments – for simplicity. Start with the lowest power, +1.00 diopter, and work your way up if needed. You may find that a lower power is all you need.

Depending on your initial test results, you can try on reading glasses with +1.00, +1.25 if you tested as a +0.75. Alternatively, try +1.00, +1.50 if you tested as a +1.0…You get the drift. The idea is to find the best pair of reading glasses to improve your vision in the areas you need most – without making things overly blurry in the distance.

Ideally, attempt to test a pair of glasses with weaker or stronger magnification than what your results yielded. Hence, when narrowing your options to two or so specifications, pick the glasses with the lowest power.

Eyeglass stores usually stock pairs of reading glasses with various powers for you to choose from. But if you still can’t decide, most stores offer free returns, so you can always order a few pairs online and return the ones that don’t work.

4. Use Online Power Finder Tools

Some people would rather not go through the hassle of testing various reading glasses. And sometimes, you may be unsure about your results. In that case, a power finder tool might come in handy to determine the right strength for your lenses.

Online power finders consider your age and may ask you to complete a short vision test. You can also key in information from a prescription for your current readers. Based on your answers, the tool provides you with a range of recommended powers for your reading glasses. Then, you can test a few pairs of reading glasses with different magnifications to find the right one.

Unfortunately, such a tool may not always be accurate as it can’t factor in your interpupillary distance or the curvature of your corneas. However, if you want a quick estimation, it may give you a ballpark idea of the reading glasses to acquire.

Although you can adopt various approaches (as outlined) to determine the strength of your reading glasses, talking to an optometrist or your eye doctor would be the best way to get an accurate prescription. But, it’s not a requirement. And once you find the right readers, all that’s left is to choose your style. To that end, I hope this guide points you in the right direction.