Abstract: Device and method for non-invasively measuring the level of glucose in blood. The device comprises a light shielded chamber, a light emitter operative to emit light in the green-turquoise (GT) wavelength range into the light shielded chamber, a detector operative to detect GT light in the GT wavelength range in the light shielded chamber, a tissue receiving area for removably receiving at least a part of a human tissue such to be housed within the light shielded chamber so that the emitted light is incident onto the human tissue, and a monitoring engine operative to determine a level of glucose in blood based on the amount of emitted and detected GT light.