Eyeglass prescriptions can be confusing at first. Below are several common prescription formats and the key information you need to understand them.
Standard Grid Format
This is the most common prescription format. It usually includes clearly labeled fields such as OD, OS, SPH, CYL, AXIS, and PD. The values may be printed or handwritten by your eye doctor.
Rx Notes:
SPH and CYL values normally include a plus (+) or minus (-) sign.
PD may appear in different formats, such as 62 for Single PD, 33/31 for Dual PD, or 62/60 for Distance PD and Near PD.
Example of a standard grid prescription.
Blank Format
A blank or free-form prescription usually contains handwritten information instead of values arranged in a printed grid.
Carefully check the labels, numbers, decimal points, and plus or minus signs before entering your prescription.
Example of a handwritten blank-format prescription.
Progressive / Bifocal
Prescriptions for progressive, bifocal, reading, or computer glasses usually include an ADD or NV value. The ADD value represents additional near-vision power and normally includes a plus (+) sign.
Rx Note:
Your prescription may also include DV for Distance Vision or NV for Near Vision.
Example of a progressive or bifocal prescription with ADD or NV values.
Prescription with Prism
A prism prescription is used to correct certain eye alignment problems, such as double vision. It normally includes two values: PRISM and BASE.
Rx Note:
BO means Base Out, BI means Base In, BU means Base Up, and BD or BDn means Base Down.
Example of a prescription containing PRISM and BASE values.
Vertical Prescription
Unlike standard prescriptions that list values from left to right, a vertical prescription displays the information from top to bottom.
This format is less common, but it normally contains the same measurements, including SPH, CYL, AXIS, ADD, and PD.
Example of a vertical prescription with values listed from top to bottom.
