# Smart Optometry vs OKN Drum

The clearest difference is update cadence: OKN Drum at every 9 days against Smart Optometry's every 4 months. Smart Optometry's advantage is rating (4.4 vs 4.1) and ratings volume (529 vs 16). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. Smart Optometry sells 10 in-app purchases, starting at $2.99 per month and OKN Drum sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Smart Optometry holds the better App Store score, 4.4 against 4.1. That said, the two scores are not equally well evidenced: Smart Optometry has 529 ratings behind it against 16, so its average is the more settled of the two. Written reviews complicate that: 42% of Smart Optometry's written reviews are positive against 46% of OKN Drum's, so the app with the better star average is not the one people write more warmly about.

Smart Optometry ships an update every 4 months, OKN Drum every 9 days. The most recent releases landed on September 20, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Smart Optometry | OKN Drum |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (529 ratings)](https://appshunter.io/ios/app/smart-optometry/id1053891266/reviews)** | [4.1 (16 ratings)](https://appshunter.io/ios/app/okn-drum-optokinetic/id6474153180/reviews) |
| Number of ratings | **529** | 16 |
| Positive reviews | 42.3% of reviews | **46.2% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 9 days** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 28 MB | 13 MB |
| Requires iOS | **13** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Hundred Vision d.o.o.](https://appshunter.io/developer/1053891265) | [My Call Bag LLC](https://appshunter.io/developer/1243282862) |

## What reviewers say

### Smart Optometry

[App page](https://appshunter.io/ios/app/smart-optometry/id1053891266)

This app offers eye care professionals a suite of 15 interactive and precise digital eye exams for patient screening and testing. It simplifies the examination process with clear guidelines, fast execution, and automated calculations, supporting a more efficient and accurate diagnostic workflow.

**Highlights:** 15 interactive digital eye exams, Automated calculation and diagnosis, Multi-language support, Vertex and visual acuity calculators, Simple and fast user interface, Precise and reliable results

**Features:** Vision Pro support

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRO Monthly Subscription | $2.99 | per month |
| PRO Yearly Subscription | $22.99 | per year |
| Visual Acuity + Test | $1.99 | one-time |
| Red Desaturation Test | $1.99 | one-time |
| Generous Tip | $4.99 | one-time |
| Generous Tip! | $4.99 | one-time |
| Smart Optometry PRO | $9.99 | one-time |
| PRO Bundle | $9.99 | one-time |
| Massive Tip! | $9.99 | one-time |
| Amazing Tip! | $14.99 | one-time |

**What reviewers like**

- 👍 Excellent product
- 👍 Beautifully designed
- 👍 Highly accurate results
- 👍 Super easy to use
- 👍 Masterfully engineered

**What reviewers complain about**

- 🐛 App crashes frequently
- 🐛 App does not open
- 🐛 App stops working
- 🐛 Requires payment for tests
- 🐛 App is full of ads

**Reported bugs**

- App crashes on startup
- App closes automatically after login
- App stops working after update
- Tests demand payment for Pro version
- Visual acuity unit converter plus button not working

**Requested features**

- Update visual acuity unit converter plus button
- Add inches option for measurement
- Provide explanations for test procedures and expected results
- Make Arabic language available
- Allow calibration of acuity test for different distances


### OKN Drum

[App page](https://appshunter.io/ios/app/okn-drum-optokinetic/id6474153180)

This app offers a digital optokinetic drum for vision testing and exercises. Customize stripe width, speed, and color, with options for pediatric targets. It also features a metronome and camera recording for eye movements.

**Highlights:** Adjustable stripe width and speed, Selectable black or red stripes, Pediatric targets (puppies, dinosaurs, animals), Full-screen mode, Integrated metronome, Record eye movements with camera, Upload custom images for drum

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $4.99 | one-time |


## Frequently asked questions

### Is Smart Optometry free?

Smart Optometry is free to download, with in-app purchases available.

### Is OKN Drum free?

OKN Drum is free to download, with in-app purchases available.

### Which has better reviews, Smart Optometry or OKN Drum?

Smart Optometry is rated higher. Smart Optometry averages 4.4 out of 5 from 529 ratings, while OKN Drum averages 4.1 from 16 ratings.

### Do Smart Optometry or OKN Drum have ads?

Neither Smart Optometry nor OKN Drum shows ads.

### Which is updated more often, Smart Optometry or OKN Drum?

Smart Optometry ships an update every 4 months, and OKN Drum every 9 days. Most recently, Smart Optometry was updated on September 20, 2026 and OKN Drum on September 22, 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.*