It’s nothing dystopian like you think. Basically just a variation on camera sensors:

[…] bio-inspired cameras that capture the world more like the human eye does. These are called dynamic vision sensors, and they work like motion detectors for each pixel. They only “wake up” and send information when something changes in the scene, rather than constantly streaming data like a regular camera.

These bio-inspired cameras are also highly energy efficient, using less than 1% of the power of normal cameras.