"The light can increase the electrical activity in neurons that are active to begin with," he explained.
One expert said these findings should put to rest any suggestion that patients exaggerate their sensitivity to light; they are not whining or imagining their symptoms.
Dr Richard Lipton, director of the Montefiore Headache Center and professor of neurology and epidemiology at Albert Einstein College of Medicine in New York City, commented that:
"This provides an anatomic and physiological basis for a common experience -- that light makes pain worse, not because you're a whiner, but because there is an anatomic pathway that links the visual system to the pathway that produces head pain." .