Facewear such as eyewear 200 includes biosensors 208 on the earpieces 204 which are arranged to detect activity of the posterior auricular muscles (102, figure 1), from which zygomaticus muscle activity is inferred, to identify facial expressions e.g. a smile, which are then fed back to the user. The biosensors preferably detect electrical activity via e.g. electromyographic (EMG) sensors, or could detect the movement or tension of skin overlying a muscle via e.g. optical, ultrasound or photoelectric means. Other muscle group activity such as temporalis, orbicularis, frontalis or glabellar muscles could be monitored or inferred. The intensity of the facial expression may be identified from the magnitude of the activity and the feedback could be visual (e.g. flashing lights or variable colour), auditory including computer-generated speech and frequency of repetition, amplitude, color or brightness might indicate the detected intensity. Control of muscle activation can be improved through use of biofeedback.