Screen Curtain

Screen Curtain is an accessibility feature available on iOS and some other platforms that turns off the device's display while keeping the device fully functional and responsive to touch input and screen reader output. Originally designed to save battery power for blind users who do not need visual display, Screen Curtain also provides a security benefit by preventing visual eavesdropping — bystanders cannot see what is displayed on screen. Blind users can continue to interact with their device through VoiceOver or other screen readers while the screen appears completely black. The feature highlights the dual-use nature of accessibility features for both usability and privacy.