How to read your Rx:

1. First off, you must identify whether you have a glasses Rx or a contacts Rx. The sample prescription above has both an eyeglasses prescription (on top) and a contact lens prescription (bottom). A contact lens prescription should specify the brand/type of the lenses and normally would also have a basecurve (BC) which should be a number usually between 8.0 and 9.2
2. The prescription may or may not have the numbers in a table format as above. Conventionally, doctors will write prescriptions with right eye (OD) on the first line, and left eye (OS) on the second line, and with the prescription numbers normally written in the following order if not specified otherwise: BC, Power, Cylinder, Axis, Add Power
3. Generally, the numbers will be obvious, as the options in the drop down menus will correspond with your numbers. If you have any doubt, you can leave the numbers blank, and we will figure it out once your order has been placed.
4. 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
5. 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