Provided are a complementary metal-oxide semiconductor (CMOS) image sensor based on a thin-film-on-application specific integrated circuit (TFA), and a method of operating the same. The CMOS image sensor may include at least one floating diffusion region formed in a semiconductor substrate, and a thin film type light sensor disposed to correspond to a plurality of pixels. The CMOS image sensor may also include at least one via electrically connected between the light sensor and the at least one floating diffusion region. The CMOS image sensor may also include a first micro lens disposed to correspond to at least two pixels of the plurality of pixels.