Monitor filter

A monitor filter is an accessory to the computer display to filter out the light reflected from the smooth glass surface of a CRT or flat panel display.^[1] Many also include a ground to dissipate static buildup. A secondary use for monitor filters is privacy as they decrease the viewing angle of a monitor, preventing it from being viewed from the side; in this case, they are also called privacy screens.

• 
  privacy screen (microscope photo)
• 
  The operating principle of a slat protection film (drawing)

The standard type of anti-glare filter consists of a coating that reduces the reflection from a glass or plastic surface.^[2] These are manufactured from polycarbonate or acrylic plastic.^[1] An older variety of anti-glare filter used a mesh filter that had the appearance of a nylon screen. Although effective, a mesh filter also caused degradation of the image quality.^[2]

Marketing names of privacy filters:

• HP's "SureView"^[3]
• Lenovo's "PrivacyGuard"^[4]
• Dell's "SafeScreen"

Support for privacy screen is available since Linux kernel 5.17 that expose it through Direct Rendering Manager and is used by GNOME 42.