We present results of conjugated polymer based devices for optical detection and image sensors. These devices have efficiencies comparable to conventional inorganic semiconductor based devices, coupled with the inherent advantage of having polymers as the active component in the device especially in terms of large area, cost effectiveness, chemical tunability and flexibility. We have adopted different strategies and device-architecture resulting in novel photodetectors; (i) p-type/n-type polymer heterostructures, with high performance in terms of photosensitivity and conversion efficiency, (ii) resonant cavity enhanced photodiodes, (iii) light responsive field effect transistors. We discuss the results and possible applications of these light detecting device structures.