How do you read an eyeglasses prescription
The first step to understanding your eyeglasses prescription is knowing what "OD" and OS" mean. They are abbreviations for oculus dexter and oculus sinister, which are Latin terms for right eye and left eye. On your RX Eyeglasses Frames, the information for your right eye (OD) comes before the information for your left eye (OS). Eye doctors write RX Glasses this way because when they face you, they see your right eye on their left (first) and your left eye on their right (second).