Have you ever seen a temporary black spot in your vision? How about jagged white lines? Something that looks like heat waves shimmering in your peripheral vision? If you have, you may have been experiencing what is known as an ocular migraine. Ocular migraines occur when blood vessels spasm in the visual center of the brain (the occipital lobe) or the retina. They can take on several different symptoms but typically last from a few minutes to an hour. They can take on either positive......