OD, OS and OU: What They Mean on Your Prescription
Eye doctors use Latin abbreviations for each eye. Mixing them up is one of the most common mistakes when ordering glasses online.
OD: right eye
Oculus dexter. Always the right eye, from your point of view, not the doctor's.
OS: left eye
Oculus sinister. Some prescriptions write OI (oculus izquierdo) or LE.
OU: both eyes
Oculus uterque. Used when a value applies to both eyes, often for ADD.
Tip
When you type your prescription online, fill the right-eye row with the OD numbers and the left-eye row with the OS numbers. Uploading a photo of your prescription avoids mistakes.
Frequently asked questions
What if my prescription says RE and LE?
RE is right eye (OD) and LE is left eye (OS).
What happens if I swap them?
If your eyes have different powers, swapping them will make your glasses blurry and uncomfortable.
Related guides
This guide is for information only and does not replace an eye exam. If you have eye pain, sudden vision loss or flashes of light, see a doctor right away.