What it means and why
OD identifies the wearer’s right eye; OS identifies the left, and OU refers to both eyes. Some records use R/L or RE/LE instead. Eye labels prevent measurements belonging to one eye from being assigned to the other.
“Right” is always the wearer’s right, not the right-hand side of a photograph viewed by another person. A table may also place the right-eye row first without placing it on the right of the page.
A worked example
Teaching example: OD has a different cylinder axis from OS. Copying the stronger spherical number correctly but swapping the rows still produces the wrong instruction. Check each complete row, including any monocular PD or height recorded separately.
What it does not tell you
Abbreviations depend on context: OD outside an eye-prescription table can mean something else. If the document layout is unclear, ask its issuer rather than inferring from a mirror or selfie.
THINK IT THROUGHWhose right does OD describe?
The wearer’s right eye, irrespective of where it appears on a screen or printed table.
Sources & reading notes
Page updated:
- AOP · Your prescription explained ↗ Professional body guidance
Explains terminology and dispensing practice; it is not a head-to-head product trial.