Branch retinal artery occlusion (BRAO) occurs when one of the small arteries supplying blood to the retina becomes blocked. This blockage can lead to sudden vision loss in the affected area of the visual field. Common causes include blood clots, atherosclerosis, or emboli, which can originate from other parts of the body. Symptoms of BRAO may include blurred or distorted vision, and in some cases, a dark spot in the vision. Diagnosis typically involves a comprehensive eye examination, including fundoscopy and imaging tests. Treatment options may vary, focusing on managing underlying conditions and preserving remaining vision.