Another main sign of occurrence of stroke is sudden outbreak of abnormal, unbearable and severe headache like migraine. The headache in such situation was explained by some of the stroke sufferers as they were struck by the lightening as many of them collapsed or felt extreme nausea after its outbreak. It can also affect the visual potential of the affected person like the spots that appear after flashing a camera or turning off the light. They start blinking to focus their vision. If the patient regularly experiences headaches or migraine then situation becomes more critical in case of stroke.