Slab-Off Calculator

Does your patient require a slab-off lens?

Use our handy slab-off calculator to help determine if a slab-off
is required for a patients prescription.


Enter sphere and cylinder values with decimal points.
Sphere Cylinder Axis
Right:
Left: O.C.
 
Result:   diopters of prism
 
Results are rounded to the nearest quarter diopter.
If the resultant prism is over 1.00 you may require a slab-off.