An optical monitor device and method are presented aimed at providing low-loss monitoring of an optical signal confined in an optical guiding structure. The image sensor device has a radiation-sensor region including a substrate and a radiation detection device, and a bonding pad region including the bonding pad structure. The user device can interpret touch gestures at a touch sensitive display used to present the UIs and can interpret the touch gestures as corresponding to one or more commands for modifying the UIs.