Optical characterisation plays a major role in differentiation of biological tissues on the basis of optical parameters like Reflection and Transmittance in a non-ionizing and non invasive manner. To study the optical parameters a Double Integrating Sphere (DIS) setup is used, to find out the intensity of light reflected and transmitted. Each sphere consists of three apertures, one for placing the sample and the second for placing the photo detector. Tissues are illuminated using LASERs, commonly He-Ne LASER (5mW, 632nm). The laser beam is illuminated through the third aperture. The photo detector measures the light intensity incident on it and converts it into current which is converted to voltage. Obtained results are validated using Monte Carlo simulation code developed using C programming code. © Research India Publications.