The issue is your being secretly watched all the time and the sensor is following you to see where your at and what your doing then taking photos to send to the spies. If you look into the camera and take a photo you will see the person.
OR you could read the specks on cell phones and realize the IR thing is a proximity sensor to detect when your face is near the phone and shut down the screen brightness.. Most cell phones have them.
Using another phone camera pointed to the sensor you will see the IR light in the viewer.
link to details. this is for older cells but the new ones have the same feature.
BlackBerry® smartphone touchscreen goes dark during a call due to the proximity sensor