The application relates to an ingestible capsule and method for in vivo imaging and/or treatment of one or more diseased areas of interest within the gastrointestinal tract of an animal or human being. The capsule comprises an image sensor; a lens system for focusing images onto the image sensor; at least one light source for illumination of the tissue area of interest, the at least one light source optionally being capable of providing optical therapeutic treatment to the diseased areas; a variable lens system located in front of the at least one light source, wherein the variable lens system comprises beam steering means and focusing means for directing and focusing the light beams from the at least one light source onto the diseased tissue areas, a control unit in communication with the image sensor, the at least one light source, and variable lens system, a power source for powering the image sensor, the at least one light source and the control unit; and a non-digestible, transparent outer protective shell configured to pass through the gastrointestinal tract, housing within the image sensor, the lens system, the at least one light source, the variable lens system, the control unit and the power source.