Automatic detection of the blood vessels in retinal images is a challenging task. In this paper a survey has been made to help biomedical engineers and medical physicists. Here we have taken three different methods for blood vessels segmentation, method (a) a novel method to segment the retinal blood vessel is used, which overcome the variations in contrast in large and thin blood vessels. Method (b) a method uses 2-D Gabor wavelet to enhance the vascular pattern and method(c) a method used is Star Networked Pixel Tracking Algorithm which is used to eradicate a noise aligned in a vessel format. These methods to segment the blood vessels so that we can easily diagnose and do treatment of several eye disorders.