According to one aspect, the invention provides an optical sensor for measuring a force distribution, comprising a substrate; one or more light emitting sources and one or more detectors provided on the substrate, the detectors responsive to the light emitted by the sources; wherein a deformable opto-mechanical layer is provided on said substrate with light responsive properties depending on a deformation of the opto-mechanical layer.The design of the sensor and particularly the use of optical components in a deformable layer make it possible to measure the contact force accurately. The sensor is scalable and adaptable to complex shapes. In one embodiment also a direction of the contact force can be determined.