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Reading Glasses Strength: What Strength Reading Glasses Do I Need?

Reading Glasses Strength: What Strength Reading Glasses Do I Need?

Author: Autumn Sprabary 


Most people expect their bodies to undergo some subtle changes as they age. But they’re often caught off guard by the natural decline in their near vision. If you find that reading small print is trickier now than it used to be, rest assured that you’re not alone.  

Presbyopia is an age-related vision change that affects more than 30 million people in the UK. It occurs when the eye's lens gradually hardens and becomes less flexible. This inflexibility makes it difficult for the lens to adjust and focus on nearby objects.


Fortunately, reading glasses are an inexpensive and accessible way to help correct the effects of presbyopia.  

Do I Need Reading Glasses? 

If you’re 40 or older, it’s very possible you need reading glasses, as presbyopia often begins around this age. Presbyopia usually progresses through your mid-60s and stabilises around age 70.  

One of the earliest symptoms of presbyopia is experiencing blurred vision when reading or engaging in other close-up tasks. If you find yourself holding books or screens at arm's length to see clearly, it could be a sign that presbyopia is setting in. 

Another indicator of presbyopia is needing more light to read clearly. If you find yourself reaching for a brighter light for near work, your eyes may be signaling the onset of presbyopia. Diminished near vision often prompts the need for brighter light to discern details clearly. 

As presbyopia progresses, the reading glasses strength you need will likely increase. So, while you may start with a lower magnification, you will probably need to update your reading glasses regularly to accommodate vision changes. 

What Are the Different Strengths of Reading Glasses? 

Reading glasses come in a variety of strengths, typically measured in dioptres (D) in increments of 0.25 or 0.50. Each level of lens magnification in readers has a plus sign (+) in front of it. The further that number is from zero, the stronger the magnification is.  

Your reading glasses strength (or level of magnification) is based on the severity of your presbyopia and the level of correction you need. Keep the following in mind when shopping different lens powers:  

Reading glasses strength +1.00 D to +1.50 

This eyeglass readers strength is suitable for mild presbyopia or people who only need a slight magnification for reading small print. It is often recommended for those in their 40s experiencing early signs of presbyopia. 

Reading glasses strength +1.50 D to +2.50 D 

People with a moderate level of presbyopia may require slightly stronger correction, which they can achieve with this range of magnification. This strength is commonly used by people in their 50s who find the lower-strength magnification no longer meets their vision needs. 

Reading glasses strength +2.50 D to +3.50 D 

This reading glasses strength is leaning toward the higher end of the spectrum. People with significant presbyopia may find this strength beneficial for tasks that require a higher level of magnification. 


Reading Glasses Strength Chart 

To find your eyeglass readers strength, use our printable dioptre reading test card below. For the best results, the card must be printed out.  

Before printing, make sure that print options such as "fit to page" are disabled before printing. Once printed, read the chart without glasses while holding the card about 35cm (14 inches) away.  

Do not try to test yourself by reading the card from your screen. 


While over-the-counter reading glasses are available in various strengths without a prescription, it's best to consult with an eye care professional if you notice any changes in your vision.  

An eye exam gives your optician a chance to check the health of your eyes and determine if anything else could be causing your difficulty reading. If they confirm you have presbyopia, they’ll ensure you know what lens strength to get in your readers to help avoid eye strain and discomfort. 

Finding the Best Reading Glasses for Your Vision Needs 

Whether you’re new to readers or ready to upgrade to a stronger magnification, Foster Grant has you covered. From reading sunglasses to our blue light reading glasses, we have everything you need to read clearly and comfortably.  

Browse our full inventory of reading glasses to find the style and magnification to fit your needs.  



  1. Presbyopia - market insight, epidemiology and market forecast - 2032. DelveInsight. April 2022. 
  2. Presbyopia. Cleveland Clinic. July 2023. 
  3. Reading glasses buying guide. FramesDirect. Accessed March 2024.* 
  4. Reading glasses: Prescription numbers explained. Eyebuydirect. June 2023.*