Prescription Decoder
Translate the codes on your eye prescription slip into plain language.
These are Latin abbreviations printed on every prescription:
- OD (Oculus Dexter): your right eye.
- OS (Oculus Sinister): your left eye.
- OU (Oculus Uterque): both eyes, when a value is the same for each.
- Minus power (−): you're nearsighted (myopia) — distance is blurry, and the lens is thicker at the edge.
- Plus power (+): you're farsighted (hyperopia) — close-up is blurry, and the lens is thicker at the center.
CYL corrects astigmatism, caused by an irregularly shaped cornea.
- CYL: the extra power needed to correct it. Blank or "0" means you don't have astigmatism.
- AXIS: a number from 1–180 giving the angle of that correction — required whenever CYL has a value.
- Only needed for bifocal or progressive lenses.
- Almost always a plus (+) power, and the same for both eyes.
The distance in millimeters between the centers of your pupils — it lines up the optical center of your lens with your eye.
- Crucial for online orders. If your doctor didn't include it, use our PD Calculator to measure it at home.
