LensWright: Optician Calc

LensWright is the calculator opticians, lab techs and ABO students actually need — and it costs $4.99 once, not $4.99 a month.

Enter the Rx once. Every calculator prefills from it.

FREE, UNLIMITED
• Sphero-cylinder transposition (plus-cyl ↔ minus-cyl)
• Spherical equivalent
• Vertex compensation — applied PER MERIDIAN and re-formed, not just on the sphere

FULL UNLOCK ($4.99, one time)
• Prentice's rule and induced prism
• Vertical imbalance with a slab-off indicator
• Oblique meridian power
• Sagitta, centre and edge thickness
• Minimum blank size
• Compound prism (resultant magnitude and direction)
• Tilt and wrap (Martin's formula)
• Saved Rx history
• Lab-order PDF export

WHY VERTEX PER MERIDIAN MATTERS
Compensating only the sphere is the classic error. A −8.00 −1.50 × 175 does not keep a −1.50 cylinder at the corneal plane — it comes back near −1.23. LensWright compensates each meridian and re-forms the prescription, so what you order is what you meant.

EVERY RESULT SHOWS ITS FORMULA
You can check the work. That is the point.

100% ON DEVICE
No account. No network. No tracking. Any prescription you enter stays on your iPhone.

For professional reference only. Always verify before ordering or dispensing.