The present invention provides a sensor for radiance based diagnostics of body tissues comprising a performing component and an adhering component, the performing component comprising at least one radiance source for radiating a tissue and at least one detector 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, and such that when operative, the adhering component hermetically fastens the performing component to the tissue to the extent that the detector only receives rays which are reflected from within 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 and perform analysis of the data received by the detector.