"Visual disturbances" refers to any changes or problems with a person's eyesight, such as blurriness, flashes of light, or seeing things that aren't there. Full definition
About 20 percent of sufferers have an aura — visual disturbances such as flashing lights and blind spots. (health.com)
There may already be beginning muscle contractions or even visual disturbances. (mypetneedsthat.com)
«Classical» migraine headaches, the kind typically preceded by visual disturbances called auras, «are mostly or entirely caused by genes», says Michael Bjørn Russell of the University of Copenhagen. (newscientist.com)