An optical touch panel including a support, an optical fiber illumination assembly arranged along and above at least part of a periphery of the support to define a detection region, the assembly including at least one optical fiber and a light source arranged for directing light along the at least one optical fiber, at least one light detector, arranged to detect changes in the light received from the optical fiber illumination assembly produced by the presence of a finger or stylus in the detection region and detection circuitry receiving at least one output from the at least one light detector and providing an output indication of the two dimensional location of finger or stylus impingement in the detection region.