glasses Rx explained

OD: Right eye. Latin for oculus dextrus.

OS: Left eye. Latin for oculus sinister.

OU: Both eyes. Latin for oculus uterque.

S | Sphere | SPH
If it's + you're farsighted. The higher the value in diopters (abbreviated D or DS), the more farsighted. If it's - you're nearsighted. The higher the value in diopters (abbreviated D or DS), the more nearsighted.

C | Cylinder | CYL
This is how much astigmatism you have, in diopters (abbreviated D). The larger the number, the more astigmatism.

Axis
If you have astigmatism, its orientation is described in degrees, between 001 and 180.

Pupillary distance | PD
The distance between your pupils! It's slightly smaller for near vision than distance. This value helps us place the optical center of your prescription where your eyes actually are, which is not necessarily at the center of the frames.

Prism
Some prescriptions have prism, measured in prism diopters. Prism has a directionality (ex. BU or base up, BO or base out). Prism helps shift the image to a position more comfortable for the wearer.