Vivid Eye Care | Cranston Market and Meadows Mile | Calgary
356 Cranston Rd SE #1020 Calgary AB T3M 0S9 (403) 724-0101
(587) 323-4302

Calgary, AB |403.724.0101

How to Read Your Eyeglass Prescription

Optometrists are bound by law to provide an eyeglass prescription after every eye exam. Yet, most people do not know how to read their own prescriptions. 

Be different! You will quickly realize that understanding your prescription is more than trivia. This record contains crucial information that you can use to better take care of your vision and your health as a whole.

Learn what your optometrist is truly seeing when they examine your eyes. Perhaps you could learn something that you would otherwise never know! 

Reading Your Eyeglass Prescription Is Easy And Fun! 

After your eye exam, your eye doctor quickly scribbles something on a small piece of paper before handing it over to you. Wishing you good luck, she sends you away to get your first pair of prescription glasses. On your way, you curiously take a peek at the small piece of paper… and notice that you do not understand a single thing written on it. 

To the uninitiated, eyeglass prescriptions might as well be a fictional language. But these records are actually very easy to read. Though not mandatory, understanding your eyeglass prescription lets you learn things about your eyes that you would otherwise not know. 

The A To Z Of Your Eyeglass Prescription 

Your prescription most likely looks like a grid with 2 rows and 5 columns. This yields 10 cells, which can be populated with numbers. 

The 2 rows are invariably designated as OS and OD, respectively. OS, which stands for “oculus sinister,” is Latin for left eye. OD, or “oculus dextrus,” denotes the right eye. 

The 5 columns are as follows: 

SPH or S (Spherical)

This column indicates whether you are nearsighted or farsighted and to what extent. 

The number that appears under this column can be either positive or negative. A positive number implies farsightedness, whereas a negative number implies nearsightedness. The closer the number is to 0, the more moderate the condition. For example, -1.00 or +1.00 represents mild nearsightedness and mild farsightedness, respectively. 

CYL or C (Cylinder)

This column indicates the extent of your astigmatism. This condition implies an irregularly shaped cornea, which causes blurred vision. 

The numbers that appear in this column follow the same principle as indicated above.

This column is left blank if you do not have astigmatism. 


This column indicates the orientation of your astigmatism. Whereas CYL indicates how much astigmatism you have, AXIS indicates where it is. 

The numbers that appear in this column range anywhere from 0 to 180 degrees. This number tells your optometrist where the curvature of the astigmatism is situated. 

If you do not have astigmatism, this column will be blank. 


This column indicates the amount of prismatic power needed in your glasses to compensate for eye alignment problems.  

The information under this column indicates the amount of prism needed and the direction of the prism to correct the condition. 

Unless you have eye misalignment, this column is unlikely to be populated. 


This column indicates how much magnifying power you need in your glasses to address presbyopia, which denotes the gradual loss of your eye’s ability to focus on close objects. 

The numbers that appear under this column are always positive and range from + 0.75 to 3.00. 

If you do not have presbyopia, this column will be blank. 

And that’s it! There should not be any more information on your prescription. While this rundown may seem like a lot to take in, your eyeglass vendor will easily understand your prescription and will be happy to explain it to you. 

Know What Your Eyeglass Prescription Says 

Becoming literate in eyeglass prescription may seem daunting at first, but the rewards are well worth it. Understanding your prescription is the same as understanding your eyes and overall health on a deeper level. For instance, if you knew what -7.00 under the SPH column meant, you would know that you should take frequent breaks at work to rest your eyes and spend more time outdoors than in front of a computer. 

To learn more about how to take care of your vision, contact Vivid Eye Care in SE Calgary today. We’re here to help!

A pair of blue translucent glasses


Q: Are eyeglass prescriptions the same as contact lens prescriptions?

No. They are not the same. An eyeglass prescription does not contain the same information as a content lens prescription. 

Q: Can I use reading glasses instead of prescription glasses?

If reading glasses make focusing on written words easier, they are fine to use. However, if your eye doctor recommends prescription glasses for you, you will have clearer results with the tailored glasses. 

Q: Can I wear contact lenses instead of prescription glasses?

The right contact lenses can be a suitable alternative to prescription glasses. Make sure you speak with an optometrist before ordering contact lenses on your own.