An apparatus and method of measuring oxygenation of tissue in a non-invasive manner are provided. The apparatus comprises a light source configured to emit a light pattern to be projected onto the tissue, in which the light pattern comprises superimposed patterns having different patterns. A detector captures an image of a reflected light pattern which is reflected from the tissue as a result of the projected light pattern. A processor coupled to the detector can be configured to perform a transform on the image of the reflected light pattern and determine oxygenation of each of a plurality of layers of the tissue in response to the transform of the image. Polarimetry can be used in determining a change in polarization angle of light beam. Tissue oxygenation can be determined at a plurality of layers from one snapshot, for example oxygenation of retinal layers.
