How do I read my soft contact lenses prescription?

A contact lenses prescription is not the same as an eyeglass (spectacles) prescription. In addition to your lens power, your contact leness prescription contains information relating the size of the lens to your eye. You may also find your prescription printed on the packing in which your contact lenses were supplied.

A typical contact lenses prescription looks like this : 

Eye	Power (Sphere)	BC (Base Curve)	DIA (Diameter)
OD	- 2.50	8.6	14.4
OS	- 2.00	8.6	14.4

OD = Right Eye   OS = Left Eye Brand Name is also included. E.g. (Acuvue, Surevue, Optima FW, etc.) 

POWER (sphere):

The strength of your contact lenses which is given as '+' or '-' with a numerical value and a decimal point, such as '+2.5' or '-7.0'. The '+' and the '-' are very important and we need to know whether your fitting is '+' or '-' when we order your lens for you. You will find that the power for your right eye (OD) may be different to the power for your left eye (OS). Your contact lenses power is not the same as that for your eyeglasses (spectacles).

Bifocal lens :

An Add Power usually from number +1.00 to +3.00.

The Base Curve which is the inside curve of your contact lenses. This is a figure with one decimal point, commonly 8.1 up to 8.9. The figure is usually the same for both eyes.

DIA:

The Diameter of your contact lenses that is recommended to fit your eye. This is a figure with one decimal point such as 13.8, 14.0 or 14.5. The lens diameter fitted is usually the same for both eyes.

If you have astigmatism, you will have been fitted with a toric contact lens.

In addition to the above specification, toric contact lenses wearers will have other figures on their prescription. These are CYL (Cylinder) and AXIS.

CYL (Cylinder):

Cylinder refers to the strength of you astigmatism. The values are typically -0.75 up to -1.75. Please note that the cylinder measurement is given with a '-' sign.

AXIS:

Axis refers to the location of your astigmatism. This measurement is given in degrees (º). The values of AXIS may range from 10º up to 180º.