Retinal images are widely used for diagnostic purposes by ophthalmolo- gists. Therefore, these images are suitable for digital image analysis for their visual enhancement and pathological risk or damage detection. Here, we implement a lu- minosity and contrast enhancement technique based on domain knowledge. We also review and analyze a previous approach in optic nerve head segmentation to extend its applicability to non circular shaped contours. We introduce a di erent strategy based on the use of active contours.