# Rule Of Conoid

> Rule Of Conoid (iPhone/iPad app by Evandro Souza.)

- Source: https://appshunter.io/ios/app/rule-of-conoid/id549151465 (this page in markdown: same URL + `.md`)
- Developer: [Evandro Souza](https://appshunter.io/developer/369811735)
- Category: Utilities, Reference
- Price: $5.99
- Age rating: 17+
- Requires: iOS 12.0 · 15 MB
- Languages: American English
- Released: 2012-08-07
- Data updated: 2025-08-09
- User reviews in markdown: https://appshunter.io/ios/app/rule-of-conoid/id549151465/reviews.md

## What is Rule Of Conoid?

RULE OF CONOID - Simulate the "circle of least confusion" on prescription eyeglasses.

This application is based on the rule of the conoid of sturm. Widely used to calculate the prescription glasses when you do not want to totally correct the astigmatism power.

With the application "Rule of Conoid" the ophthalmologist can calculate in a simple and practical way the astigmatism to prescribe in cases of high aniseikonias. The application reduces the amount of prescription of astigmatism, maintaining the accommodative balance and the "circle of least confusion" on the retinal plane.

More info:
https://medical-dictionary.thefreedictionary.com/conoid+of+Sturm
https://pt.slideshare.net/DrSamarthMishra/sturms-conoid-64617238

*** This application is for reference only and simulations***


## Version history (last 5 releases)

### 2.1 — 2024-03-25

Compatibility with the latest version of iOS 17.0

### 2.0 — 2020-10-26

Completely redesigned application;
Clean and pleasant interface;
iOS 13 Compatibility.
Button to save or share the results.
More info about Sturm's conoid:
https://medical-dictionary.thefreedictionary.com/conoid+of+Sturm

### 1.2.1 — 2019-10-08

Fixed an issue when running on some iOS 10.3 devices

### 1.2 — 2019-10-05

iOS12 compatibility

### 1.1 — 2016-03-02

iOS 9 compatibility;
Graphical improvements;
Other minor bugs fixed.

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## More apps by Evandro Souza

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- [Best Deal - The easiest and fastest way to compare prices.](https://appshunter.io/ios/app/best-deal/id608113768)

All apps by Evandro Souza: https://appshunter.io/developer/369811735

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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 2025-08-09.*