ELI5: What are Screen Filters/Privacy Screens?
A privacy screen is a thin cover for your laptop that makes the screen look black to anyone peeking from the side. Only the person sitting right in front can see what’s on the screen — like blinders for your computer.
Definition
Screen filters (privacy screens) are physical overlays applied to monitors or laptop screens that use micro-louver technology to restrict the viewing angle to the user directly in front of the screen. People viewing from the sides see only a black screen, preventing shoulder surfing attacks where an unauthorized person reads sensitive information displayed on a screen.
Key Details
- Uses micro-louver technology (like window blinds on a microscopic scale)—narrows the effective viewing angle to ~30° from the front.
- Protects against shoulder surfing in public places, open offices, airports, coffee shops, and shared workspaces.
- Available in sizes for laptops, desktops, and mobile devices; can be removable or permanent.
- A simple, low-cost, and effective preventive physical control for visual eavesdropping.
- Should be combined with screen lock policies (automatically lock after inactivity) for comprehensive visual security.
Connections
- Parent: physical-security — a physical control against visual eavesdropping
- See also: shoulder-surfing