Crossed Cylinder Calculator 4+
Alta Vista LLC
Designed for iPad
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- $1.99
Screenshots
Description
Determine resultant lens over existing lens combined with over refraction. Makes contact lens fitting more accurate. Useful in refining high powered eyeglass prescriptions using over refraction. Quick and easy to use application determines resulting contact lens prescription or spectacle prescription using lens currently worn and over refraction data. Exact results or round to one quarter diopter.
What’s New
Version 1.12
Code update
Ratings and Reviews
Axis error
Past version
This app has a drum system and is easy to use, I have found some glitches. Firstly, the axis drums have an erroneous axis of 169 which should be 160. Secondly, a negative axis appears. This is not a big problem in that by subtracting that number from 180 gives the correct axis. For example, if lens worn is +2.50-1.75x167 and the Over Refraction is Plano-0.25x30, the result is +2.50-1.75x-9. -9 is equivalent to x171.
Update:
Axis problem is fixed. Recommend increasing range of spheres to + / - 20D. Or having an optional window to type in the needed power.
Typing in an axis may save time spinning the drum.
Axis incorrect
I would gladly change my rating if this bug is fixed but I can’t find anywhere to contact the developer. It calculates axis wrong. If you enter +2.00-1.75x175 for glasses and over refract 0.00-0.50x90 the result it gives is +1.51-1.26x83 (it won’t round this result either), which is incorrect.
I cannot currently recommend purchasing this app until the error is corrected.
App Privacy
The developer, Alta Vista LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Information
- Seller
- Alta Vista LLC
- Size
- 16 MB
- Category
- Medical
- Compatibility
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- iPhone
- Requires iOS 9.0 or later.
- iPad
- Requires iPadOS 9.0 or later.
- iPod touch
- Requires iOS 9.0 or later.
- Mac
- Requires macOS 11.0 or later and a Mac with Apple M1 chip or later.
- Apple Vision
- Requires visionOS 1.0 or later.
- Languages
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English
- Age Rating
- 4+
- Copyright
- © Copy Right 2022 Alta Vista LLC All rights reserved.
- Price
- $1.99
Supports
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Family Sharing
Up to six family members can use this app with Family Sharing enabled.