Contact Lenses Prescription - how to read it
Yes, I know, prescriptions can be daunting at first glance. However, they contain standard elements and with little explanation you should be able to read your contact lenses prescription and understand it easily. This will help you determine which lenses and parameters to order.
A standard prescription should contain the following information:
Description:
- OS: Left Eye
- OD: Right Eye
- OU: Both Eyes
Brand Name:
- Manufacturer & Series of lens
Power/Sphere (SPH):
- Strength of lenses - a number between –20.00 and +20.00
Base Curve (BC):
- Back curvature of lens - a number between 8.0 and 10.0, or a phrase such as flat or steep
Diameter (DIA):
- Diameter of lens - a number between 13.0 and 15.0
If you have an astigmatism and needs toric lenses, your prescription will also need to say:
Cylinder (CYL):
- Correction for Astigmatic patients (toric lenses only) - a number between -4.00 and +4.00
Axis:
- Correction for Astigmatic patients (toric lenses only) - a number between 0 and 180
It is important that the prescription contain the brand name of the lenses, as different brand names are made with different materials and have not the same measurements.