Find the values for each eye: usually labeled **OD** (right) and **OS** (left)
Identify **SPH** (Sphere): the main focusing power for distance or near
Identify **CYL** (Cylinder): the amount of astigmatism correction
Identify **AXIS**: the astigmatism direction in degrees (0–180)
Identify **ADD** (Addition): the near-vision boost for bifocals/progressives
Identify **PRISM** (if present): may include **PRISM** power for alignment (often with base direction like **Base Up/Down/In/Out**)
Identify **PD** (Pupillary Distance): may be **distance PD** and/or **near PD**
Note **values may include signs**: minus (−) often indicates nearsighted; plus (+) often indicates farsighted
Record **right and left separately**: use the OD values for the right eye and OS values for the left eye
For glasses with no astigmatism: **CYL** may be **0.00** and **AXIS** may be omitted
For single-vision prescriptions: **ADD** is typically not present
For progressive/bifocal prescriptions: **ADD** is usually present and applies to both eyes (or may be different per eye)
If your prescription includes **VA/visus** or other medical codes, use the optical powers (**SPH/CYL/AXIS/ADD/PD**) for ordering lenses
If your prescription includes **“DS”** instead of **SPH/CYL**: it’s a sphere-only value (no astigmatism listed)