A computer-implemented method of classifying the optic nerve head, the method comprising operating one or more processors to: segment an image of an optic nerve head from a photographic image of an eye; segment the image of the optic nerve head into multiple segments each containing blood vessels and neuroretinal rim fibres; extract features from the segmented images, the features describing relationships between the blood vessels themselves and between the blood vessels and the neuroretinal rim fibres in each of the segmented images, identify characteristics of the optic nerve head based on the extracted features; and classify the image of the optic nerve head based on the identified characteristics, characterized in that the relationships between the vessels themselves and between the blood vessels and the neuroretinal rim comprise vectors mapped between points on the blood vessels themselves and vectors mapped between points on the blood vessels and points on the neuroretinal rim in each of the segmented images, the method comprising for each segment: superimposing multiple concentric circles on the segment, determining intersection points of the circles with blood vessels and branches thereof and the neuroretinal rim fibres, mapping vectors between the intersection points, determining distances of the vectors, determining ratios of the vector distances, combining sequences and/or permutations of the ratios into an image representation, searching a lookup table for the closest representation to the image representation, and classifying the optic nerve head according to the closest representation found. segment an image of an optic nerve head from a photographic image of an eye; segment the image of the optic nerve head into multiple segments each containing blood vessels and neuroretinal rim fibres; extract features from the segmented images, the features describing relationships between the blood vessels themselves and between the blood vessels and the neuroretinal rim fibres in each of the segmented images, identify characteristics of the optic nerve head based on the extracted features; and classify the image of the optic nerve head based on the identified characteristics, characterized in that the relationships between the vessels themselves and between the blood vessels and the neuroretinal rim comprise vectors mapped between points on the blood vessels themselves and vectors mapped between points on the blood vessels and points on the neuroretinal rim in each of the segmented images, the method comprising for each segment: superimposing multiple concentric circles on the segment, determining intersection points of the circles with blood vessels and branches thereof and the neuroretinal rim fibres, mapping vectors between the intersection points, determining distances of the vectors, determining ratios of the vector distances, combining sequences and/or permutations of the ratios into an image representation, searching a lookup table for the closest representation to the image representation, and classifying the optic nerve head according to the closest representation found. superimposing multiple concentric circles on the segment, determining intersection points of the circles with blood vessels and branches thereof and the neuroretinal rim fibres, mapping vectors between the intersection points, determining distances of the vectors, determining ratios of the vector distances, combining sequences and/or permutations of the ratios into an image representation, searching a lookup table for the closest representation to the image representation, and classifying the optic nerve head according to the closest representation found.