The present invention provides a sensor (20) for radiance based diagnostics of body tissue including a performing component (21) and an adhering component (23). The performing component includes at least one radiance source (22) for radiating a tissue, and at least one detector (24) for detecting rays emitted from the radiance source. The adhering component is capable of fastening the performing component to a tissue such that the radiance source, and detector are facing and contiguous with the tissue. When operative, the adhering component fastens the performing component to the tissue to the extent that the detector receives only rays which are transmitted through or reflected from the tissue. The sensor may include a controlling device which senses external conditions and which is capable of controlling the sensor in response to the sensed conditions. The sensor may also be in communication with an electronic circuit, which may control the radiance source, and/or detector, performing analysis of data received by the detector.