A system and method for determining volume-related parameters of a biological tissue, such as ocular tissue, include a light source for projecting light towards the biological tissue, a receiver for receiving light reflected from the biological tissue at two spectral wavelengths, and an image acquisition system in communication with the receiver for forming an image from the reflected light at each wavelength. A processor applies a mathematical model to the image which compares the absorption of light by the biological tissue at a selected image point at each of the two spectral wavelengths to determine the volume-related parameters, such as the relative thickness and material properties, of the biological tissue at that location.