What are SPH, CYL, and AXIS in Eye Prescription?

Do you know how to read your prescriptions? What are SPH, CYL, and AXIS?

All these are used for the vision correction measurement. This article is going to tell you how to read your prescription correctly.


What do OD and OS mean?

OD: an abbreviation for Oculus Dexter, which means “Right Eye.”

OS: an abbreviation for Oculus Sinister, which means “Left Eye.”

So the values concerning the correction of your right eye will be indicated as “OD,” while the left eye is “OS.”

What is SPH?

SPH or Sphere is the lens power required and prescribed to correct either farsightedness or nearsightedness. It is in the unit known as diopters (D).

If there is a minus sign next to your SPH prescription, it means you are nearsighted. If there is a plus sign next to it, you are farsighted.

What is CYL?

CYL or Cylinder is used to identify how much lens power in your prescription is for astigmatism if you suffer from it. It may be that nothing is filled in for that part of the prescription. That basically means you either have no or minor astigmatism that needs to be corrected.

You will find that the number for this column in your prescription again either has a (-) minus sign or a (+) plus sign as a reference to whether it is nearsighted astigmatism or farsighted astigmatism correction.

Cylinder power will always come after sphere power in a glasses prescription.

What is AXIS in prescription?

An AXIS will only be found on your prescription if there is a CYL value for the same eye. The AXIS, in degrees, is a number between 0 and 180. It is used to correctly orientate the cylinder correction when making your glasses. On some rare occasions, you may find an AXIS value with a decimal place or fraction.


1. What does OU mean?

OU is the abbreviation that means both eyes. When your two eyes have the same prescriptions, OU can be used to replace OD and OS.

2. How long does it take for prescription glasses to be ready?

Ordinarily, the prescription glasses should take 5-7 business days to be ready. But how long it will take depends on your prescription, frame, and lens choices.