Blinding a surveillance camera can be done with multiple ways.

Firstly, you can blind a camera using a flashlight, an infrared laser, and shine the light directly into the lens.

Secondly, you can obscure the lens with tape, clothing or anything opaque.

When properly executed, these techniques should create a lens flare, or lens block that makes it nearly impossible for the camera to view the area. Block Detection aims to detect when the lens vision is obscured and this can be use to alert personnel of such activity.

This feature is important in preventing criminals or anyone from accidentally from blinding camera vision.