Your iPhone features an ambient light sensor located near the front-facing camera that constantly monitors the lighting conditions in your environment. Based on this sensor data, the iOS operating system automatically dims your screen in dark rooms to prevent eye strain and cranks the brightness up to maximum when you step outside into direct sunlight. While this “Auto-Brightness” feature is highly convenient and generally helps conserve battery life, it can occasionally be overly aggressive or fail to provide the exact brightness level you prefer. You can completely disable it and take manual control.
How to Turn Off Auto-Brightness
Apple has moved this setting out of the main Display menu and hidden it inside the Accessibility settings.
- Open the Settings app on your iPhone.
- Scroll down and tap on Accessibility (the blue icon with a white figure).
- Under the “Vision” section, tap on Display & Text Size.
- Scroll all the way down to the very bottom of this menu.
- Locate the toggle switch labelled Auto-Brightness.
- Tap the green switch to move it to the Off position (the toggle will turn grey).
Your iPhone’s screen brightness will now remain completely static, regardless of how bright or dark your surrounding environment becomes. You will need to manually adjust the brightness slider located in your Control Center whenever you want to change the illumination level of your display.