Abstract: The present invention relates to a system for automatically evaluating oxygen saturation of the optic nerve and retina, said system comprising: image capturing system further comprising: a fundus camera (26), a four wavelengths beam splitter (27), a digital image capturing device (28), a computer system, image processing software performing in real-time the steps of: registering set of multi-spectral images (1) by, binarizing the multi-spectral image (7), find the all the border regions of each image by finding the region including the straight line that passes the most number of points in the region (8), use the orientation of the borders to evaluate the orientation of each spectral image (9), equalize the orientation of each spectral image by rotating the spectral image (10), edge detect each spectral image (11), estimate the translation between the spectral images based on the edges of adjacent images (12), transform the images to a stack of registered images (13), locating blood vessels (2) in each of the