
Almost everyone who wears glasses has been handed a prescription slip and walked out of the office with only a vague sense of what it says. The abbreviations are clinical, the numbers seem arbitrary, and the format varies enough between practices that even experienced glasses wearers find themselves confused when switching providers or shopping online. Here’s what it all actually means.
The Basic Structure of an Eyeglass Prescription
A standard eyeglass prescription is divided into two eyes: OD (oculus dexter, or right eye) and OS (oculus sinister, or left eye). Some prescriptions add OU, which refers to both eyes together. …




