---
title: amount
framework: healthkit
role: symbol
role_heading: Instance Property
path: healthkit/hkvisionprism/amount
---

# amount

The strength of the correction.

## Declaration

```swift
@NSCopying var amount: HKQuantity { get }
```

## Discussion

Discussion This is the total correction strength, measured in prismDiopter() units.

## See Also

### Accessing lens specification data

- [eye](healthkit/hkvisionprism/eye.md)
- [HKVisionEye](healthkit/hkvisioneye.md)
- [angle](healthkit/hkvisionprism/angle.md)
- [horizontalAmount](healthkit/hkvisionprism/horizontalamount.md)
- [horizontalBase](healthkit/hkvisionprism/horizontalbase.md)
- [verticalAmount](healthkit/hkvisionprism/verticalamount.md)
- [verticalBase](healthkit/hkvisionprism/verticalbase.md)
- [HKPrismBase](healthkit/hkprismbase.md)