---
title: prism
framework: healthkit
role: symbol
role_heading: Instance Property
path: healthkit/hkglasseslensspecification/prism
---

# prism

An object that contains information about the eye alignment correction.

## Declaration

```swift
@NSCopying var prism: HKVisionPrism? { get }
```

## See Also

### Accessing the specification’s data

- [farPupillaryDistance](healthkit/hkglasseslensspecification/farpupillarydistance.md)
- [nearPupillaryDistance](healthkit/hkglasseslensspecification/nearpupillarydistance.md)
- [vertexDistance](healthkit/hkglasseslensspecification/vertexdistance.md)