Find Your Lens Power

In order to calculate the lens power needed for each eye, please use the calculator below. The calculator uses the following equation to calculate diopter strength for each eye:

DIOPTER STRENGTH = 1/2 of the CYLINDER + SPHERE

Sphere Cylinder Diopter Strength
O.D. (right eye)
+
-
+
-
O.S. (left eye)
+
-
+
-

As a rule of thumb, always round down to a diopter strength that is one step lower than the calculated value. For example, if the calculated diopter strength for the left eye is 5.0, round down to 4.5.

How to Interpret an Eye Prescription

add prism_base axis cylinder sphere odos distance
Hover over the boxes in the prescription on the left to understand what each section is about.