Automatic segmentation of retinal blood vessels can help diagnose eye diseases like diabetic retinopathy and glaucoma earlier by supporting specialists. A method is proposed using a MATLAB code to preprocess 45 fundus images through grayscale conversion, contrast enhancement, intensity adjustment, complementing, and adaptive histogram equalization. Blood vessel segmentation then applies morphological opening, binarization, and noise extraction. The method achieved 97% specificity, 69% sensitivity, and 94% accuracy on the HRF database.