Lentes

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  App Icon

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Inspiration

I wear glasses, and I realized something surprisingly basic: I didn't have a good answer to “What is my current prescription?”

Prescriptions end up on pieces of paper, PDFs, photos, emails, or forgotten in a drawer. Then there is everything around the prescription: which glasses use it, where I bought them, the receipt, when I should have another eye exam, and — for contact-lens users — how many lenses are actually left.

Apple Health can store vision prescriptions, but getting information there and making it useful in everyday life still requires a good experience around it.

That became Lentes: a private, native iPhone home for your vision records.

What it does

Lentes starts with the prescription itself.

You can scan a glasses prescription with the camera, extract values such as SPH, CYL, AXIS, ADD, prism and pupillary distance, review the result, correct anything that was not recognized properly, and save the confirmed prescription to Apple Health.

But I wanted the app to cover the lifecycle around that prescription too.

Lentes can:

• Store glasses and contact-lens prescriptions
• Save confirmed vision prescriptions to Apple Health
• Keep photos, shops, prices and receipts for each pair of glasses
• Track contact-lens inventory and estimate when you will run out
• Record daily lens usage from the app, a widget, notifications or Siri
• Create refill reminders
• Keep track of eye exams
• Compare prescriptions and spending over time
• Organize records into separate family profiles
• Surface the right information through Siri and system integrations

The goal is deliberately simple: when you need something related to your vision, you should know where it is.

Building Lentes

Lentes is built as a native Apple-platform application rather than a web service wrapped inside an app.

A major part of the work was integrating the app with the system instead of recreating features that iOS already provides. HealthKit is used for vision prescriptions, while widgets, App Intents/Siri, notifications, Reminders and Calendar make information available where it is actually useful.

I also spent considerable time on the data model. A prescription is not just a screenshot or a block of text: right and left eyes have different values, prescriptions change over time, glasses belong to particular prescriptions, contact lenses have inventory, and every record may belong to a different family member.

For Shipaton, I also wanted the business model to respect the character of the utility. The essential experience is free for one person, while Lentes Pro unlocks unlimited records, family profiles, insights and additional organization features.

Pro is a single lifetime purchase rather than another subscription. RevenueCat handles the entitlement and purchase infrastructure while the app remains focused on the user's records.

Challenges

The biggest challenge was turning something that looks simple — “save my glasses prescription” — into structured data without making the interface feel like a medical database.

Scanning is another example. OCR can help read a prescription, but prescriptions come from different opticians, countries and systems, with different layouts and terminology. For information this important, automation should assist the user rather than silently pretend to be correct. That is why Lentes follows a Scan → Check → Save workflow: extracted values remain visible and editable before anything is stored.

Family support introduced another challenge. Records have to remain clearly associated with the correct person, particularly when interacting with Apple Health, which is inherently personal to the device owner.

What I learned

The biggest lesson was that a small utility can have considerable depth when it integrates properly with the operating system.

Instead of asking how many features I could add, I repeatedly asked: where should this information naturally live?

Sometimes the answer is Lentes. Sometimes it is Apple Health. Sometimes it is a Home Screen widget, Siri, a notification, Reminders, or Calendar.

Building Lentes became an exercise in making those pieces behave like one coherent product.

And now, when someone asks me what my glasses prescription is, I finally have a better answer than searching through my camera roll.

Built With

• cloudkit
• codex
• ios
• swift