Normally, your eyeglasses prescription will be in “Standard Grid Format,” although your doctor may opt to write it out free-form.
When in grid format, the values are typically typed out via computer but maybe handwritten by your doc.
Once you understand the abbreviations used, you will be able to understand the prescription no problem!



Here are the abbreviations you’ll need to know when learning how to read your prescription:


OD - This stands for “Oculus Dexter” and refers to your right eye. (It’s Latin, so it sounds a little weird—don’t let it throw you off!)


OS - “Oculus Sinister,” referring to the left eye.


SPH - “Sphere.” This value indicates your farsightedness and/or nearsightedness.


CYL - “Cylinder.” The presence of this value indicates astigmatism. Specifically, CYL means the lens power needed to correct it. Both CYL and SPH are always accompanied by a plus (+) or minus (-) sign.


AXI - “Axis.” This is the other value that indicates astigmatism. Specifically, AXI indicates the curvature of your cornea.


PS - “Pupillary Distance,” which represents the distance between your two pupils. This measurement helps ensure the center of your lens is placed correctly, so it’s pretty important. (Want to learn more about pupillary distance and how to measure it yourself?