If you already have a pair of glasses, you can compare the measurements to your current frame. Just look inside your temple to find your frame measurements. The overall frame size is a combination of lens and bridge's width measurements.
Lens Width Bridge Width Temple Length
XS < 42 mm < 16 mm < = 128 mm
S 42 mm - 48 mm 16 mm - 17 mm 128 mm - 134 mm
M 49 mm - 52 mm 18 mm - 19 mm 135 mm - 141 mm
L > 52 mm > 19 mm > = 141 mm

How to read your Rx:

  1. First off, you must identify whether you have a glasses Rx or a contacts Rx. A contacts Rx should have the name or type of contacts as well as your vision correction numbers.
  2. The prescription may or may not have the numbers in a table format as above. The above prescription may have been written as: Acuvue2 OD: 8.7/14.0 -2.00 etc... in which case, you will have to determine which parameter is which. Generally, the numbers will be obvious, as the options in the drop down menus will correspond with your numbers. If you have any doubt, please give us a call.
  3. The following terms are used interchangeably in most prescriptions:
    OD = Right Eye and OS = Left Eye.
    Power = Sphere
    Cyl = Cylinder
    Ax = Axis
    BC = Base Curve
    Dia = Diameter
  4. If your prescription indicates that you have an astigmatism (i.e. you need toric contact lenses), sometimes the cyl and axis are written this way: 8.7/14.0 -2.50 -1.00x70
    In this case, the cyl would be -1.00 and the axis would be 70
Sample Prescription