The term ocular migraine, also called an ophthalmic migraine, is used to describe two different conditions, according to the Mayo Clinic. The first is a painless migraine aura that may or may not be accompanied by a headache. The second, a rarer and more severe type, also called retinal migraine, is a short period of unilateral blindness or decreased vision that occurs right before or during a headache.
Vision Loss
Ocular or retinal migraine can cause complete vision loss in one eye for a period lasting from 10 to 60 minutes, according to the Merck Manual. According to a 2004 article published in Current Neurology and Neuroscience Reports by S. Pradhan and S. Chung, 50 percent of ocular migraines involve complete temporary vision loss in one eye, and 12 percent reported some vision loss. According to Pradhan and Chung, 19 percent of patients with ocular migraine reported blurred vision and 7 percent reported dim vision.
Scomatas
When a person suffers from scomata, her area of vision is decreased---in essence, she has a bigger blindspot. According to Pradhan and Chung, 13 percent of patients experiencing ocular migraines have scomatas. Scomatas may move across the visual field, and may look like zigzagging, shimmering spots or stars, according to the Mayo Clinic. Flashing lights may also be reported, according to a 2005 Canadian Medical Association Journal (CMAJ) written by K. Gan.
Headaches
Unlike migraine auras, ocular migraines are always accompanied by a headache occurring at the same time as the ocular migraine or within 60 minutes after, according to the criteria established for the definition of ocular migraines by the International Headache Society. The headache must have the same characteristics of the headache experienced in migraine without aura. The headache causes moderate to severe pain, is located in one area, pulsates and is aggravated by activities of daily living, like climbing stairs.
Other Symptoms
To qualify as an ocular migraine by the International Headache Society standards, the ocular symptoms must be accompanied by or followed within 60 minutes by nausea and vomiting with sensitivity to light and sound.
