Symptoms of an ocular migraine will usually affect both eyes and include flashes of light, blind spots, a zigzag pattern across the field of vision and shimmering spots, according to Mayo Clinic. These symptoms are usually not serious and are temporary.
Ocular migraines should not be confused with retinal migraines. A retinal migraine is a headache which is accompanied or preceded by diminished vision or blindness, usually in only one eye. If this happens, seek the advice of an eye specialist immediately, as it is usually a sign of a more serious condition, says Mayo Clinic.
Some people who suffer from ocular migraines have other symptoms besides changes in vision. Many complain of numbness that can accompany or precede the headache and many patients have the vision changes without a headache coming on. Ocular migraines are not typically a cause for concern and will go away on their own.
Symptoms of an ocular migraine may present themselves 20 to 30 minutes before the onset of a headache and the intensity of the headache will range from mild to severe, often lasting for several hours.
Although the cause for these migraines remains a mystery, many doctors believe the flashes of light and other symptoms are caused by a cortical spreading depression. This phenomenon causes a negative effect in the electrical impulses in the brain.