Last updated: July 17, 2026
LensTracker ("the app", "we", "us") is built to help you track contact lens wear and eye care habits. This policy explains what data the app collects, why, and what control you have over it. LensTracker is a wellness tool, not a medical device, and this policy applies to that context.
| Data type | Purpose | Where it's stored |
|---|---|---|
| Wear sessions, product & stock records | Core app functionality | Your device, synced via iCloud (CloudKit) |
| Sleep & heart rate variability (Apple Health, optional) | Shown as supporting context near your Eye Health Score — never used to calculate it | Your device only, never uploaded to our servers |
| Location (approximate, optional) | Weather-based wear recommendations | Sent to Open-Meteo for a forecast lookup, not stored by us |
| Account identity (Sign in with Apple) | Authentication, subscription status | Supabase (auth & subscription database) |
| AI chat messages & insights requests | Generating your daily insights and chat responses | Processed via our Cloudflare Worker proxy and the Claude API — not stored beyond what's needed to generate a response, and not used to train AI models |
| Subscription status | Unlocking Premium features | Apple (StoreKit), validated server-side via Supabase |
If you grant HealthKit access, LensTracker reads sleep and heart rate variability data to show it as context alongside your eye care routine. This data never leaves your device, is never sent to our servers or any third party, and never factors into your Eye Health Score calculation. You can revoke this access anytime in Settings → Privacy & Security → Health.
Daily insights and AI chat (Premium features) send relevant app data — such as recent wear patterns and, if you've enabled it, comfort ratings — to our Cloudflare Worker, which forwards the request to the Claude API to generate a response. This data is used only to produce your response and is not retained for model training.
You can delete your account and all associated data at any time from Settings → Delete Account inside the app. This removes your data from your device and from iCloud sync. This action is permanent and can't be undone.
LensTracker is not directed at children and we do not knowingly collect data from users under 13.
If this policy changes in a way that affects how your data is handled, we'll update the "Last updated" date above and, for material changes, notify you inside the app.
Questions about this policy or your data: lens-support@vaclav-kraus.cz