A UV and visible light transparent film material is secured onto or within a touch-based screen to automatically disinfect the external surface. UV light is emitted from a UV light source into an edge of the transparent film material in order to transfer the UV light through the transparent film material while remaining in the transparent film material through total internal reflection effect. Some UV light exits the transparent film material at points of contact to disinfect fingertips and immediate surrounding areas through the frustrated total internal reflection effect.
