How Do Reading Glasses Work?

Over 32 million Americans wear some form of over-the-counter reading glasses (OTC readers) to help their vision. Some may use readers to help them focus on words up close, while others may use readers to keep their eyes comfortable while reading and focusing on smaller objects. 

Reading glasses are common and have a variety of benefits for the eyes. However, if you’re considering investing in the perfect pair of readers, it’s important to understand how they work and what they do.

Read on to discover the science behind reading glasses.

Reading Glasses 101

Reading glasses can be a great solution to blurriness and difficulty focusing on words and objects up close. They’re commonly used by older adults, as general wear and tear can take a toll on our eyes and make it harder for our eyes to focus. If you tend to hold menus farther away in order to see them, you may need a pair of readers. How do reading glasses do this? 

What Do Reading Glasses Do?

Reading glasses enlarge things like text so that it’s easier to focus on them. Your readers will have a lens strength in them which determines how large the text will appear. There are varying degrees of generic strengths, ranging from +0.25 to +0.7.00, and the text will get bigger depending on the reading glasses strength you choose.

It’s important to note that reading glasses are used for farsightedness or “hyperopia.” This is represented by the plus sign that accompanies reading glasses strengths. People who are farsighted can see distant objects well, but not so much up-close objects.

A minus sign indicates nearsightedness. Much like glasses that are used to correct astigmatism, glasses that correct nearsightedness are known as “prescription readers.” An optometrist or ophthalmologist will need to perform a comprehensive eye examination to give you these types of prescription lenses. 

Instead of holding the menu farther away in order to focus on the words, reading glasses will enlarge the text and help your eyes focus on them at a normal distance! Why do people have trouble focusing on words up close in the first place? 


One of the most common reasons for using reading glasses involves presbyopia. Presbyopia is a condition that takes place as we get older. It generally begins at age 40 and develops until age 65. While it may sound intimidating, it’s completely normal and quite simple to fix! Here’s some of the science behind what causes presbyopia and how it can change our eye’s lens.  

The cornea and the lens are two important structures in our eyes that help us see. They’re responsible for refracting light that enters our eyes so that our retina is able to sharpen the image that our brains process. 

The cornea bends light which the lens muscle in our eyes contracts in order to focus the image. When looking at an object or word up close, the lens muscle constricts, while if looking at a word or object far away, this muscle relaxes. These muscular movements of our eyes are essential to seeing and focusing.

Over time, however, the lens of the eye can become less flexible and unable to constrict properly to focus on words or objects. This results in presbyopia— a difficulty focusing on words and objects up close. Reading glasses come in handy because they enlarge text and objects, helping the lens of your eyes focus on them without needing to hold your book or phone at arm’s length in order to see.

Who Can Use Reading Glasses?

Many people associate reading glasses with impaired vision, but this is not the case. Anyone can use reading glasses. Most people look for reading glasses to enjoy decreased eye strain and easier quality of life. 

Reading glasses can be prescribed by an eye doctor, but they don’t have to be, nor do you need an eye exam or a prescription for readers. In other words, reading glasses are accessible to anyone! Whether you have presbyopia or just want additional comfort for your eyes while reading, you can wear reading glasses. 

It’s also important to note here that reading glasses won’t damage your eyes if you have perfect vision. They are made to enlarge words and text but won’t hurt your vision if you wear them all day (even while you’re not reading) or if you don’t “need” them to see. 

Types of Reading Glasses and What They Do

Now that we’ve taken a closer look at how reading glasses work, what they do, and how they help the lens of our eyes focus on words and objects up close, let’s explore different types of reading glasses and what they do.

Multifocal Reading Glasses

If you like to wear your readers all day and need to switch focus often, multifocal reading glasses might be right for you. Multifocal reading glasses have multiple lens segments that perform different roles for your eyes.

So, if you need to change focus from distance vision or interacting with others, looking at your computer monitor, and reading, this type of glasses contains all these strengths in one. Some multifocal reading glasses have three lens segments, while others only have two. These are known as bifocal reading glasses, and they come with an unmagnified portion and a lower lens portion where you can insert the reading glasses strength of your choice. 

Reading Sunglasses

Reading sunglasses are like regular sunglasses, except they have the reading glasses strength of your choice throughout the entire lens. These still offer the UVA and UVB protection you need to keep your eyes safe and relaxed in the glare of the bright sun while giving you the lenses you need to focus on nearby words and objects with ease. 

If you work outside, garden, or read on the back porch, you’ll be able to take advantage of tinted lenses while still being able to focus well.

Computer Reading Glasses

If you spend a lot of time at your computer, on your phone, or looking at a digital screen, consider a pair of computer reading glasses

In addition to the magnification powers of reading glasses, computer glasses can also help filter potentially harmful blue light. Our screens emit blue light that may be potentially harmful when our eyes are overexposed to it. So, if your life involves tablet, cell, or computer use, a pair of computer glasses can help filter 30% of potentially harmful blue light* while you work. 

If you’re reading on a digital reading device, answering emails, or simply scrolling the web, you can use computer reading glasses as an excellent way to keep your eyes comfortable and happy.

Find the Right Readers for You

Reading glasses are a common accessory for those with presbyopia or simply want to make life a little easier on their eyes. Readers help magnify text and objects so the cornea and lens muscles of your eyes can focus with ease. 

Finding the right reading glasses for you is easy with this guide to buying reading glasses. Once you choose the type of reading glasses you want to use, simply find the strength lenses you need and find a frame shape and style you want. With the affordable, high-quality glasses at®, it is easy to match your glasses to your favorite outfits or your favorite color for a look that is undeniably you. 


Eye Gear Blue Light Disclaimer:

*Potentially harmful blue light refers to the 415-455 nanometer range of the visible light spectrum. The percentage represents the average amount of potentially harmful blue light filtered at 5 nanometer increments in this range.



 Previous What Is Presbyopia? | AAO  

Blue Light and Your Eyes | Prevent Blindness 

Refraction of Light | Georgia State University