Abstract: Devices (1) comprising light detectors (11-14) for detecting light and in response generating detection information, and light-guiding layers (15) comprising outer sides for guiding incident light (21) arriving at the outer sides and originating from input devices (20) towards the light detectors (11-14) are provided with converters (16) for converting the detection information into further information for taking into account one or more angles between the incident light (21) and an axis perpendicular to the light-guiding layer (15). As a result, one/two-dimensional corrections of locations of incidence can be made, and one/two-dimensional estimations of directions of user locations can be made, to adapt device parameters such as rotation, zooming, scrolling, volume, contrast, brightness or sound optimizing parameters, or to select a user from a plurality of users operating their own input devices (20).