---
title: diopter()
framework: healthkit
role: symbol
role_heading: Type Method
path: healthkit/hkunit/diopter()
---

# diopter()

Returns a HealthKit unit for measuring the optical power of a lens using diopter units.

## Declaration

```swift
class func diopter() -> Self
```

## See Also

### Constructing vision units

- [prismDiopter()](healthkit/hkunit/prismdiopter().md)