Read your prescription
Right Eye (OD)
OD stands for the latin phrase, oculus dexter, or "right eye". Prescriptions always list information for the right eye first. If both the right and left eyes have the same prescription, sometimes the abbreviation OU is used instead (ocular uniter, or “both eyes”).
Left Eye (OS)
OS stands for the latin phrase, oculus sinister, or “left eye”.
This number represents the spherical power of a lens in diopters. This number is equivalent to the reciprocal of the lens focal length.
This measurement indicates the power needed for a bifocal or multifocal lens. At this time Cirrus Eyewear does not sell multifocal or progressive lenses because the measurements needed to ensure correct fit for these lenses must be made by a qualified optician while the patient is trying on the specific frames to be purchased. These measurements (including vertex distance and pantoscopic tilt correction are not provided on the prescription).
The axis indicates astigmatic orientation in degrees. This measurement designates where the cylinder correction should be located in degrees (90-180) and is usually preceded by an “x”.