You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All are true about central retinal aery occlusion (CRAO) except and explain in detail?
Answer- C. Sudden painful loss of visionPatient notices sudden painless loss of vision.Patients's with a patent cilioretinal aery may retain central vision as the macula is spared.Emboli are the most common cause of retinal aery occlusion.Obstruction occurs at the level of lamina cribrosa.The larger retinal aeries are constuicted and look like thin threads while the smaller vessels are scarcely visible.The fundus appears milky white because of retinal edema.There is cherry-red spot at the macula.Blood column within the retinal veins is segmented (Cattle tracking)