---
title: heroEye
framework: coremedia
role: symbol
role_heading: Type Property
path: coremedia/cmformatdescription/extensions-swift.struct/key/heroeye
---

# heroEye

Indicates which of the two eyes should be used as the primary when rendering in 2D. It is usually perpendicular to the target image surface.

## Declaration

```swift
@backDeployed(before: macOS 26.0, iOS 26.0, visionOS 26.0)
static var heroEye: CMFormatDescription.Extensions.Key { get }
```