# IOL vs 9 Gaze

The clearest difference is rating: 9 Gaze at 4.6 against IOL's 3.6. 9 Gaze also leads on review sentiment (86% vs 75%). IOL's advantage is update cadence (weekly vs every 2 months) and iOS requirement (11.2 vs 13.0). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

9 Gaze holds the better App Store score, 4.6 against 3.6. Both are backed by a comparable volume of ratings — 9 and 22 respectively. Written reviews point the same way: 75% of IOL's written reviews are positive against 86% of 9 Gaze's.

IOL ships an update weekly, 9 Gaze every 2 months. Both last shipped on November 6, 2026.

## The numbers

| Metric | IOL | 9 Gaze |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.6 (9 ratings)](https://appshunter.io/ios/app/iol-calculator/id456304691/reviews) | **[4.6 (22 ratings)](https://appshunter.io/ios/app/9-gaze/id1173442389/reviews)** |
| Number of ratings | 9 | **22** |
| Positive reviews | 75.0% of reviews | **85.7% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Weekly** | Every 2 months |
| Monetization | Free | Free |
| Size | 1 MB | 36 MB |
| Requires iOS | **11.2** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Columbia University](https://appshunter.io/developer/405514802) | [See Vision, LLC](https://appshunter.io/developer/1173442388) |

## What reviewers say

### IOL

[App page](https://appshunter.io/ios/app/iol-calculator/id456304691)

This medical tool assists in calculating intraocular lens power for cataract surgery. It provides essential calculations for ophthalmologists and eye care professionals.

**Highlights:** Intraocular lens power calculation, Cataract surgery assistance, Medical calculation tool, Ophthalmology aid

**Features:** Vision Pro support

**In-app purchases:** none


### 9 Gaze

[App page](https://appshunter.io/ios/app/9-gaze/id1173442389)

This app helps document eye motility and strabismus in nine cardinal positions. It offers an on-screen guide for consistent eye positioning and automatically creates composite images for easy exporting. Users can add strabismus measurements and email or save images for medical records.

**Highlights:** Document eye motility and strabismus, On-screen guide for eye positioning, Automatic composite image creation, Add strabismus measurements, Selfie or standard mode, Email or save images

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is IOL free?

IOL is free to download, with no in-app purchases.

### Is 9 Gaze free?

9 Gaze is free to download, with no in-app purchases.

### Which has better reviews, IOL or 9 Gaze?

9 Gaze is rated higher. IOL averages 3.6 out of 5 from 9 ratings, while 9 Gaze averages 4.6 from 22 ratings.

### Do IOL or 9 Gaze have ads?

Neither IOL nor 9 Gaze shows ads.

### Which is updated more often, IOL or 9 Gaze?

IOL ships an update weekly, and 9 Gaze every 2 months. Most recently, IOL was updated on November 6, 2026 and 9 Gaze on November 6, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*