Visual Acuity Charts Privacy Policy

Last updated: October 2026

This Privacy Policy explains how the Eye Charts mobile application (the "Application") on iOS and Android handles your information. We are committed to protecting your privacy and designing an application that functions offline with minimal data requirements.

Please read this Privacy Policy carefully. By installing and using the Application, you agree to the practices described in this policy.

1. Offline Operation and Local Data Storage

The Application is designed as an offline-first tool to measure visual acuity:

  • No Account Required: You do not need to register, create an account, or log in to use the Application.
  • Vision Test Results: By default, test scores are not recorded. If you enable "Record Scores" in the Application settings, your test scores are stored strictly on your local device.
  • No Cloud Sync: Your vision scores are never uploaded to our servers or shared with any third parties.
  • Data Deletion: You can clear your data at any time through the app settings. Uninstalling the Application will permanently delete all locally stored scores and application artifacts.

2. Information Collected When You Use Online Features

All core vision-testing features work completely without an internet connection. An internet connection is only used when you explicitly choose to contact support or access online help.

A. Support Messages

When you voluntarily send a message to the developer via the in-app support feature, the message transmits:

  • Optional Contact Information: Your name and email address (if you provide them to receive a reply).
  • Message Body: The text or feedback you write.
  • Diagnostic Information: Technical details to assist with troubleshooting, including the app name, app version, operating system, OS version, device manufacturer, device region, and UI language. This diagnostic information is used solely to solve technical issues and is not used to identify you personally.

Do not include sensitive personal information unless it is necessary for your support request.

B. Server Log Data

When the Application connects to our backend server (hosted on Microsoft IIS or Apache) to transmit support messages or load online help:

  • The server automatically records standard web request logs, including your device's public Internet Protocol (IP) address, the date and time of the request, and the requested resource.
  • These logs are used solely for common network security, preventing abuse, and routine server diagnostics.

3. Device Permissions

The Application requests only the minimum device permissions necessary to function:

  • Android Permissions:
    • android.permission.INTERNET: Used to send support messages and open online help pages, obtain the device support information and access online help contents.
    • android.permission.VIBRATE: Used to provide optional haptic feedback during vision tests.
  • iOS Permissions: On iOS, the Application does not request additional device permissions.

4. Third-Party Services and Tracking

  • No Third-Party Analytics: We do not use third-party analytics frameworks (such as Google Analytics or Firebase) to track user behavior.
  • No Advertising: The Application contains no advertisements or tracking technologies.
  • No Third-Party Links: The Application only links to the official documentation and privacy policy hosted under our official domain (visualacuity.info). It does not contain links to external third-party websites.

5. Children's Privacy (COPPA / GDPR)

The Application is designed to test distant visual acuity, including for children aged 6 and older.

  • The Application does not solicit or collect personal information from children.
  • All test scores remain on the local device.
  • Children should not submit support messages or provide personal contact details without parental or guardian consent.

6. Legal Bases for Processing (GDPR / UK GDPR)

If you reside in the European Economic Area (EEA) or the United Kingdom, our lawful bases for handling your data are:

  • Consent: When you voluntarily provide your email and name to receive technical support.
  • Legitimate Interests: To maintain server security, resolve reported technical bugs, and ensure the reliability of the Application.

7. Data Retention and Your Rights

  • Retention: Local data remains on your device until deleted or uninstalled. Support messages and server logs are retained only as long as necessary to address your inquiry and satisfy technical security requirements.
  • Your Rights: Under applicable privacy laws (including GDPR, CCPA/CPRA, and PIPEDA), you have the right to request access to, correction of, or deletion of any personal information you have submitted to us (such as support communications). Because we do not store accounts or identifiers, please provide your email address when making a request so we can locate your messages.

8. Changes to This Privacy Policy

We may update this Privacy Policy from time to time to reflect operational or legal changes. We will update the "Last updated" date at the top of this document when changes occur. We encourage you to review this policy periodically.

9. Contact Us

If you have any questions, comments, or requests regarding this Privacy Policy, please contact us at: