The first consists of a migraine aura that results in visual symptoms, but the headache may not be present. This is due to migraine physiology affecting the part of the brain responsible for processing visual information. Both eyes are affected. Commonly occurring features include flashes of light, zigzag patterns and/or blurring. These symptoms may expand over the visual field before resolving, usually within an hour. A healthcare professional can make this diagnosis based on the description of symptoms alone, particularly when there is a personal and/or family history of migraine, although diagnostic testing is sometimes required to rule out other causes.
Retinal migraines, which are relatively rare, are also referred to as ocular migraines. Retinal migraines only affect one eye. They occur in association with a migraine headache and symptoms consist of loss of vision with occasional flashing lights. The duration of vision loss is less than one hour. However, loss of vision affecting one eye may be due to a more serious problem, and prompt medical attention is required, even if the symptoms have resolved.