What Does Balance Mean on an Eyeglass Prescription?

As with most things in life, finding balance for your vision is essential, which is one reason why regular eye exams are important. While balance can refer to several things when it comes to eyeglasses, such as the comfort, style, and fit of your glasses or frames, there is a specific meaning for the term balance when it is used on your eyeglasses prescription.

Balance on an eyeglass prescription means both eyes are prescribed the same lenses, and it is normally used when one eye has no vision or does not need vision support. A balanced eyeglass prescription is often used for cosmetic purposes more than corrective purposes—so that your eyes and lenses look the same even though you may only need vision support for one eye.  

Why Would an Optometrist Prescribe Balanced Lenses? 

Some people can experience diminishing vision in one eye, while others may require a prosthetic eye but experience visual challenges in their other eye. A balanced lens prescription is used to provide consistency across a person’s lenses when they only need vision correction in one eye. 

A balanced prescription not only helps support your vision but can also provide a consistent look across both lenses. Different glasses prescriptions can make your eyes appear larger or smaller. An optometrist can prescribe balanced lenses to help ensure your lenses look the same and have the same effect on the appearance of both eyes. 

How Do You Read Your Eyewear Prescription?

An eyeglass prescription can look very confusing if you’re not familiar with the symbols and terminology used for glasses and lenses. But your eyeglass prescription might also be easier to understand than you think.   

Your eye care team can help you understand and read your prescription, but learning what the different symbols mean now can also help you understand your prescription and communicate clearly during an eye exam. 

What Do the Letters On a Glasses Prescription Mean?

For some people, a glasses prescription can look like a spreadsheet. There are generally 2 sets, or rows, of numbers, used to record your prescription for each eye. Each row can have multiple categories for measuring different parts of your vision and eye health.

We can help you understand what each letter means and what each category is for. Feel free to follow along with your prescription in hand. When in doubt, reach out to our doctors at Eye Care Plus and we’ll be happy to guide you through your prescription. 

Here are the common categories and symbols used for eyeglasses prescriptions, as well as their meanings:

• OD, or oculus dexter, refers to your right eye.
• OS, or oculus sinister, refers to your left eye. 
• SPH is shorthand for sphere and refers to the lens power recommended for correcting your vision for both nearsightedness and farsightedness.
• CYL is shorthand for cylinder and refers to the lens power needed to correct astigmatism.
• AXIS is another measurement used for lenses that support those with vision affected by astigmatism.
• ADD refers to the magnifying power needed in the bottom of bifocal and multifocal lenses designed to support those with presbyopia. 
• PD stands for pupillary distance and refers to the distance from the center of one pupil to the center of the other. This measurement is used to determine the right fit for your glasses.
• PRISM is a measurement of the lens power needed to provide clear vision for those experiencing challenges caused by eye alignment. Prism can be measured as BO (base out), BI (base in), BU (base up), and BD (base down) in reference to where the thickest edge of a lens sits. 

How Is Lens Power Measured?

Have you ever wondered what those tiny numbers are on the corner of reading glasses? They’re a unit of measurement called diopters and are used to calculate a lens’s ability to focus. 

Nearsightedness (blurry distance vision) has a minus sign before the numbers, and farsightedness (blurry vision up close) has a plus sign before the numbers. 

Let’s say your prescription is -2.35; this means you have a diopter of 2.35 for nearsightedness. The higher the number, the stronger a prescription you’ll need to correct the condition.

You’ll notice these measurements under the SPH measurement for each of your eyes.

Book Your Eye Exam Today

Having an understanding of what a balanced eyeglass prescription is and how to read your prescription can help you better prepare for your next eye exam. 

When it’s time for your next thorough eye exam, book an appointment at Eye Care Plus. A complete assessment of your eye health doesn’t have to be difficult to understand. We strive to help you gain a full understanding of your eye health with advanced technology and compassionate care.