An optical, or more commonly "ocular," migraine is a type of migraine headache accompanied or followed by loss of vision. It is a rare condition, according to WebMD. It affects only one of the eyes.
Symptoms of optical migraines include flashing lights, blind spots and blindness, as well as a moderately or severely painful, pulsing headache. This headache typically affects just one side of the head and worsens during physical activity, as outlined on WebMD. It may also be accompanied by nausea, vomiting and heightened sensitivity to light or sound.
Although the cause of optical migraines is unknown, it could be a result of blood vessel spasms in the retina.