Proximity sensor arrangement, comprising an optical barrier being placed between a light emitting device and a photo-detector, wherein - the light emitting device, the photo-detector and the optical barrier are covered by a cover having a first surface facing away from and a second surface facing towards the light emitting device and the photo-detector; characterized in that - the optical barrier comprises a three-dimensional column-shaped body and is being designed to block light emitted from the light emitting device to the photo-detector and reflected by the cover by means of specular reflection; wherein - the light emitting device, the photo-detector and the optical barrier are positioned within a first plane (x, y) with the light emitting device and the optical barrier extends at least along the principal axis (z) being orthogonal with respect to the first plane (x, y) and directed towards the cover; and - the optical barrier is being designed to pass the light emitted from the light emitting device to the photo-detector via the cover and scattered off of objects to be placed on a first surface of the cover facing away from the light emitting device and the photo-detector, wherein: - the optical barrier extends along the first principal axis (x) being essentially parallel to the first surface; and - the extent along the first principal axis (x) is such that specular reflection paths of light emitted from the light emitting device to the photo-detector via the first and second surfaces (41, 42) are frustrated, while light scattered off of objects to be placed on the first surface is allowed to go around the optical barrier to reach the photo-detector by indirect or diffusively scattered paths via diffuse scattering. - the light emitting device, the photo-detector and the optical barrier are covered by a cover having a first surface facing away from and a second surface facing towards the light emitting device and the photo-detector; characterized in that - the optical barrier comprises a three-dimensional column-shaped body and is being designed to block light emitted from the light emitting device to the photo-detector and reflected by the cover by means of specular reflection; wherein - the light emitting device, the photo-detector and the optical barrier are positioned within a first plane (x, y) with the light emitting device and the optical barrier extends at least along the principal axis (z) being orthogonal with respect to the first plane (x, y) and directed towards the cover; and - the optical barrier is being designed to pass the light emitted from the light emitting device to the photo-detector via the cover and scattered off of objects to be placed on a first surface of the cover facing away from the light emitting device and the photo-detector, wherein: - the optical barrier extends along the first principal axis (x) being essentially parallel to the first surface; and - the extent along the first principal axis (x) is such that specular reflection paths of light emitted from the light emitting device to the photo-detector via the first and second surfaces (41, 42) are frustrated, while light scattered off of objects to be placed on the first surface is allowed to go around the optical barrier to reach the photo-detector by indirect or diffusively scattered paths via diffuse scattering.