Understanding an Eyeglass Prescription:

OD is the right eye

OS is the left eye

There are 3 parts to an Eyeglass RX
Spherical or SPH

Cylinder or CYL

&

Axis

If the patient has Astigmatism, their RX will contain CYL & AXIS

If the patient does not have Astigmatism, there are only numbers following the Spherical or SPH areas on the RX Sheet.

Eyewear Prescriptions are measured in diopters.

Eyewear Prescriptions are either +Plus Powers or -Minus Powers.

-1.00 is read: Minus 1 Diopter

+0.50 is read: Plus half Diopter

Attached is an image to help understand every area of a written prescription