When it comes to using facial recognition technology in surveillance systems, China leads the way. Now, one of the country's high schools is utilizing the technology to monitor students' facial expressions, letting teachers know what emotions the kids are experiencing.

The Hangzhou No. 11 Middle School is trialing the tech as part of its "Smart Classroom Behaviour Management System." The three cameras placed above the blackboard analyze pupils by scanning them every 30 seconds and determining if they're happy, confused, angry, surprised, fearful, or disgusted. They are also designed to log six types of student behaviors: reading, writing, hand raising, standing up, listening to the teacher, and leaning on the desk.

Hangzhou Network reports that the system can alert a teacher if a student's attention level falls below a certain point. Not only can it be used as a teaching aid, but it's also able to monitor class attendances by checking students' faces against a database.

Unsurprisingly, the use of the cameras has raised privacy questions as they are recording minors, but school vice principle Zhang Guanchao says the images themselves are not saved and the results are stored on a local server instead of the cloud.

One student said the system was having the desired effect. "Beforehand in some classes that I didn't like much, sometimes I would be lazy and do things like take naps on the desk or flick through other textbooks. Since the school has introduced these cameras, it is like there are a pair of mystery eyes constantly watching me, and I don't dare let my mind wander."

It's not just pupils that the cameras are observing; they're also being used to monitor the performance of teachers. The school claims this will help improve teaching techniques, though it's unlikely that the educators (and pupils) will appreciate being continually watched.

China already has around 170 million CCTV cameras, with 400 million more arriving over the next three years. Many of these feature some form of AI, including facial recognition.

Last month saw facial recognition tech pick out a suspect from a crowd of 50,000 in China. And reports from earlier this year revealed that some of the country's police have started using glasses with embedded facial scanning technology.