---
title: HKPrismBase.down
framework: healthkit
role: symbol
role_heading: Case
path: healthkit/hkprismbase/down
---

# HKPrismBase.down

The prism’s base is at the bottom of the lens.

## Declaration

```swift
case down
```

## Discussion

Discussion You can only use this value for the prism’s verticalBase.

## See Also

### Prism Base

- [HKPrismBase.none](healthkit/hkprismbase/none.md)
- [HKPrismBase.up](healthkit/hkprismbase/up.md)
- [HKPrismBase.in](healthkit/hkprismbase/in.md)
- [HKPrismBase.out](healthkit/hkprismbase/out.md)