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# isLuminanceReduced

A Boolean value that indicates whether the display or environment currently requires
reduced luminance.

```
var isLuminanceReduced: Bool { get set }
```

## Discussion

When you detect this condition, lower the overall brightness of your view.
For example, you can change large, filled shapes to be stroked, and choose
less bright colors:

```
@Environment(\.isLuminanceReduced) var isLuminanceReduced

var body: some View {
    if isLuminanceReduced {
        Circle()
            .stroke(Color.gray, lineWidth: 10)
    } else {
        Circle()
            .fill(Color.white)
    }
}
```

In addition to the changes that you make, the system could also
dim the display to achieve a suitable brightness. By reacting to
`isLuminanceReduced`, you can preserve contrast and readability
while helping to satisfy the reduced brightness requirement.

> Note: On watchOS, the system typically sets this value to `true` when the user
> lowers their wrist, but the display remains on. Starting in watchOS 8, the system keeps your
> view visible on wrist down by default. If you want the system to blur the screen
> instead, as it did in earlier versions of watchOS, set the value for the
> <doc://com.apple.documentation/documentation/BundleResources/Information-Property-List/WKSupportsAlwaysOnDisplay>
> key in your app’s
> <doc://com.apple.documentation/documentation/BundleResources/Information-Property-List>
> file to `false`.

---

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