Segmenting blood vessel from the retinal image is important for detecting many retinal vascular disorders. Diseases
which are all affecting the blood vessels of the eye are known as Retinal vascular disorders. Vessel separation of retinal image
is a fundamental step in finding the affected area of vascular. Some of the disorders of retinal vascular are Diabetic
Retinopathy (DR), Hypertensive Retinopathy, Retinal Vein Occlusion (RVO), Central Retinal Artery Occlusion (CRAO), and
Glaucoma. For identifying diseases and changes in the retina Retinal Blood Vessel Separation (RBVS) is important. For
segmenting the blood vessel and early detection of these disorders many different approaches and algorithms have been
developed; few of them were discussed in this paper. In this paper, various existing approaches, methodologies, and algorithms
for separating the vessels from the retinal image were analyzed.