Chairside and research tools — vertexing, prism, acuity conversions, etc.
Calculate contact lens power from a spectacle Rx.
Calculate a spectacle Rx from a contact lens Rx.
Calculate lens power given two vertex distances.
Magnitude and orientation of oblique Fresnel prism.
Estimated residual astigmatism from corneal Ks.
Convert between plus and minus cylinder form.
Visual acuity from letter size and distance.
Visual acuity from cycles per centimeter and distance.
Convert neutralizing lenses and beam angle to plus/minus cyl.
Convert base curve units (mm and diopters) or use a chart.