# Visual Vertical vs OKN Viewer

The clearest difference is price: OKN Viewer at $1.99 against Visual Vertical's $11.99. OKN Viewer also leads on rating (3.7 vs 2.0) and update cadence (every 3 months vs every 38 months). On review sentiment, ratings volume, ads and in-app purchases there is nothing between them.

Visual Vertical costs $11.99 and OKN Viewer $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

OKN Viewer holds the better App Store score, 3.7 against 2.0. Both are backed by a comparable volume of ratings — 5 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Visual Vertical ships an update every 38 months, OKN Viewer every 3 months. The most recent releases landed on November 6, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | Visual Vertical | OKN Viewer |
| --- | --- | --- |
| Price | $11.99 | **$1.99** |
| Rating | [2.0 (5 ratings)](https://appshunter.io/ios/app/visual-vertical/id419017746/reviews) | **[3.7 (3 ratings)](https://appshunter.io/ios/app/okn-viewer-nystagmus/id6695726882/reviews)** |
| Number of ratings | **5** | 3 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 38 months | **Every 3 months** |
| Monetization | Paid | Paid |
| Best chart rank | — | **#130** |
| Size | 10 MB | 1 MB |
| Requires iOS | 16.6 | **16.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 12+ | 4+ |
| Developer | [Clear Health Media](https://appshunter.io/developer/419017749) | [ishida yuto](https://appshunter.io/developer/1582923433) |

## What reviewers say

### Visual Vertical

[App page](https://appshunter.io/ios/app/visual-vertical/id419017746)

This medical app offers a quick, accurate, and low-cost method for measuring subjective visual vertical. It's designed for neurologists and vestibular rehabilitation specialists to test patients, especially for brainstem lesions and otolithic function, using just an iPhone or iPad.

**Highlights:** Measure subjective visual vertical, Accurate and low-cost testing, Suitable for neurology and vestibular rehab, Tests for brainstem lesions, Evaluates otolithic function, Multiple readings and averaged results, Single, one-off readings

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

**In-app purchases:** none


### OKN Viewer

[App page](https://appshunter.io/ios/app/okn-viewer-nystagmus/id6695726882)

**Currently charting:** #130 Top Paid · Medical (US App Store)

This app allows users to observe and experience optokinetic nystagmus (OKN) by displaying a customizable moving stripe pattern on their smartphone screen. Users can record their eye movements with the front camera for later review, making it a useful tool for medical, educational, and general interest purposes.

**Highlights:** Adjustable stripe width, Adjustable moving speed, Customizable stripe color, Record eye movements with front camera, Preview/review tool for medical settings, Visual teaching material

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

**In-app purchases:** none


## Frequently asked questions

### Is Visual Vertical free?

Visual Vertical costs $11.99, with no in-app purchases.

### Is OKN Viewer free?

OKN Viewer costs $1.99, with no in-app purchases.

### Which has better reviews, Visual Vertical or OKN Viewer?

OKN Viewer is rated higher. Visual Vertical averages 2.0 out of 5 from 5 ratings, while OKN Viewer averages 3.7 from 3 ratings.

### Do Visual Vertical or OKN Viewer have ads?

Neither Visual Vertical nor OKN Viewer shows ads.

### Which is updated more often, Visual Vertical or OKN Viewer?

Visual Vertical ships an update every 38 months, and OKN Viewer every 3 months. Most recently, Visual Vertical was updated on November 6, 2026 and OKN Viewer on November 8, 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.*