OD = right eye
OS = left eye
OU = both eyes
SPH or Sphere = lens power for nearsightedness or farsightedness
Minus sign (-) = nearsightedness
Plus sign (+) = farsightedness
CYL or Cylinder = lens power for astigmatism
AXIS = direction of astigmatism correction, measured in degrees from 1 to 180
ADD = extra magnifying power for reading or near vision
Prism = correction for eye alignment
Base = direction of prism
PD = pupillary distance, the distance between the centers of the pupils
VA or Visual Acuity = vision sharpness
Example format: OD -2.00 -1.25 x 180
Example format: OS -1.50 -0.75 x 170
If CYL and AXIS are listed, both are needed together
If ADD is listed, it is usually for bifocal or progressive lenses
If no CYL is listed, the prescription may be spherical only
If no AXIS is listed, there is no astigmatism correction
If a value is marked DS, it means no cylinder power
If a value is marked Plano or PL, it means zero power
If a value is marked NV, it refers to near vision
If a value is marked DV, it refers to distance vision