Which eye is od

What do all these letters and numbers mean? OD vs. Nearsighted prescriptions. Glasses Prescription. Distance OD OS. Sphere Cylinder Axis Prism Base Add. Pupilary distance PD : Hover on the prescription form to find out what all those number and abbreviations mean. Prescriptions with prism correction. How often should you get an eye exam?

What does Sphere, Cylinder and Axis mean? What is a strong eye prescription? Most of the time you will find that your eyeglass prescription is written in a grid-like format. It will contain terms, abbreviations, and numbers. Along the left-hand side, you might see these abbreviations. Here is what those abbreviations mean:.

Along the top, you might see different verbiage that generally has to do with measurements related to different aspects of your vision. SPH- This is short for sphere, and basically tells you how powerful your prescription needs to be in order to correct your vision. If you happen to see the letters ADD, this is how much more power you need if you are getting bifocals or progressive lenses.

CYL- This is short for cylinder. Pl — Plano. Axis — This provides information on the orientation of the cylinder power. Add — This is the reading prescription that corrects for presbyopia. Contact lenses need extra measurements and have additional terms and abbreviations. Here is a brief summary of some terms you may see on your contact lens prescription:. BC — Base curve. This is a measurement of how flat or steep a lens is. The contact lens prescription will also contain information on the power of the contact lens, the brand and type, and the expiration date.

Lenses are made with many designs and features to optimize vision. Some of the terminology used to describe these features include:. BF — Bifocal. A lens in which the distance prescription is placed on the top of the lens. The near prescription is placed on the bottom portion of the lens and marked by a line. PAL — Progressive addition lenses. These lenses progress from distance to intermediate to near prescription without a distinct line. AR — Anti-reflective.

This is a coating on lenses that reduces glare. PD — Pupillary distance. This is the distance between the center of the pupils of the left and right eyes in millimeters. SH — Segment height.