# LensWright: Optician Calc — Vertex, prism, transposition

> Vertex, prism, transposition (iPhone/iPad app by Donald Proctor.)

- Source: https://appshunter.io/ios/app/lenswright-optician-calc/id6790553187 (this page in markdown: same URL + `.md`)
- Developer: [Donald Proctor](https://appshunter.io/developer/1861592032)
- Category: Medical, Productivity
- Price: Free
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English
- Released: 2026-08-26
- Data updated: 2026-08-27
- User reviews in markdown: https://appshunter.io/ios/app/lenswright-optician-calc/id6790553187/reviews.md

## What is LensWright?

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.


## Version history (last 1 release)

### 1.0 — 2026-08-26

No release notes.

## More apps by Donald Proctor

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All apps by Donald Proctor: https://appshunter.io/developer/1861592032

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-27.*