Understanding Your Prescription

Decode the elements of your eyeglass lens prescription so you can make an informed purchase from the comfort of your home. 

Breaking Down Your Prescription

An eyewear prescription typically includes several abbreviations and numbers that indicate the type and strength of correction your eyes require.

Let’s break it down step by step:

1. OS and OD

OD (Oculus Dexter): Refers to your right eye. OS (Oculus Sinister): Refers to your left eye. If you see OU (Oculus Uterque), it applies to both eyes.

2. SPH (Sphere)

This number indicates the degree of correction needed for nearsightedness or farsightedness.

Negative (-): Corrects nearsightedness (myopia). Positive (+): Corrects farsightedness (hyperopia).

3. CYL (Cylinder)

If present, this value addresses astigmatism, a condition caused by an irregularly shaped cornea. The number can be negative or positive and is often accompanied by the Axis.

4. AXI (Axis)

The Axis (0 to 180 degrees) specifies the orientation of the astigmatism correction. A higher number does not mean more severe astigmatism; it’s simply a directional reference.

5. ADD (Addition)

Found in prescriptions for bifocals or progressive lenses, ADD indicates additional magnifying power needed for reading or close-up tasks.

6. Prism

Rarely included, this value is for correcting eye alignment issues. It is measured in prism diopters, representing the amount of correction needed to adjust for misalignment. The number specified indicates the degree of prism applied to help align the visual images properly.

Tips For Accuracy

1.

Ensure your prescription is up-to-date, typically within 1-2 years.

2.

Double-check all numbers before submitting your prescription.

3.

If anything is unclear, consult with your optometrist or our service team.